Biomedical subjects

Donna Spiegelman

Publications and source records attributed to Donna Spiegelman.

At least 19 recordsLinked to original sources

PubMed2007

Alcohol consumption and risk for coronary heart disease among men with hypertension.

BACKGROUND: Heavy alcohol consumption increases risk for hypertension, which is in itself a strong risk factor for cardiovascular disease (CVD). However, data on the association between alcohol consumption and CVD among individuals with hypertension are scarce. OBJECTIVE: To assess whether alcohol consumption is inversely associated with CVD among men with hypertension. DESIGN: Prospective cohort study. SETTING: United States. PARTICIPANTS: 11,711 men with hypertension from the Health Professionals Follow-Up Study. MEASUREMENTS: Alcohol consumption was assessed every 4 years by using a food-frequency questionnaire. Incident cases of nonfatal myocardial infarction (MI), fatal coronary heart disease, and stroke were documented from 1986 to 2002. RESULTS: During follow-up, 653 patients with MI were documented. Compared with patients abstaining from alcohol, the hazard ratio for participants with MI consuming 0.1 to 4.9 grams of alcohol per day was 1.09 (95% CI, 0.86 to 1.37); consuming 5 to 9.9 grams of alcohol per day was 0.81 (CI, 0.60 to 1.08 g/d); consuming 10 to 14.9 grams of alcohol per day was 0.68 (CI, 0.51 to 0.91 g/d); consuming 15 to 29.9 grams of alcohol per day was 0.72 (CI, 0.54 to 0.97 g/d); consuming 30 to 49.9 grams of alcohol per day was 0.67 (CI, 0.48 to 0.94 g/d); and consuming 50 or more grams of alcohol per day was 0.41 (CI, 0.22 to 0.77 g/d) (P < 0.001 for trend). Associations were similar for fatal and nonfatal MI. Alcohol consumption was not associated with total death or death due to CVD. Risks for total and ischemic stroke for patients consuming 10 to 29.9 g of alcohol per day were 1.40 (CI, 0.93 to 2.12) and 1.55 (CI, 0.90 to 2.68) compared with that of abstainers. When corrected for measurement error in alcohol consumption, dietary variables, and body mass index, the hazard ratio for participants with MI per 12.5 grams per day increment of alcohol intake was 0.68 (CI, 0.46 to 1.00). LIMITATIONS: Hypertension, alcohol consumption, and CVD risk factors were assessed by self-report. Available data used to correct for measurement error were primarily restricted to dietary variables. CONCLUSIONS: In this population of men with hypertension, moderate alcohol consumption was associated with a decreased risk for MI but not with risks for total death or death due to CVD. As in the general population, men with hypertension who drink moderately and safely may not need to change their drinking habits.

Adult↗

PubMed2006

Dietary carotenoids and risk of colorectal cancer in a pooled analysis of 11 cohort studies.

Dietary carotenoids have been hypothesized to protect against epithelial cancers. The authors analyzed the associations between intakes of specific carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein + zeaxanthin, and lycopene) and risk of colorectal cancer using the primary data from 11 cohort studies carried out in North America and Europe. Carotenoid intakes were estimated from food frequency questionnaires administered at baseline in each study. During 6-20 years of follow-up between 1980 and 2003, 7,885 incident cases of colorectal cancer were diagnosed among 702,647 participants. The authors calculated study-specific multivariate relative risks and then combined them using a random-effects model. In general, intakes of specific carotenoids were not associated with colorectal cancer risk. The pooled multivariate relative risks of colorectal cancer comparing the highest quintile of intake with the lowest ranged from 0.92 for lutein + zeaxanthin to 1.04 for lycopene; only for lutein + zeaxanthin intake was the result borderline statistically significant (95% confidence interval: 0.84, 1.00). The associations observed were generally similar across studies, for both sexes, and for colon cancer and rectal cancer. These pooled data did not suggest that carotenoids play an important role in the etiology of colorectal cancer.

Carotenoids↗

PubMed2006

Incidence of metabolic syndrome in a cohort of HIV-infected adults and prevalence relative to the US population (National Health and Nutrition Examination Survey).

BACKGROUND: Metabolic syndrome increases the risk of cardiovascular outcomes and type II diabetes. Most of the metabolic abnormalities defining metabolic syndrome are observed in HIV. OBJECTIVE: To determine the incidence and risk factors for metabolic syndrome in HIV-infected adults in the Nutrition for Healthy Living (NFHL) study (2000-2003) and prevalence relative to the findings of the National Health and Nutrition Examination Survey (NHANES) (1999-2002). METHODS: Metabolic syndrome is > or =3 of the following: hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, hypertension, abdominal obesity, and high serum glucose. The baseline prevalence of metabolic syndrome in the NFHL study (n = 477) was compared to that in the NHANES (n = 1876), adjusted for age, race, gender, poverty, exercise, and diet. RESULTS: Almost one quarter of NFHL subjects had metabolic syndrome. Most with metabolic syndrome (77%) had low HDL and hypertriglyceridemia plus > or =1 additional abnormality. The prevalence of metabolic syndrome was significantly lower in HAART and non-HAART users compared with NHANES participants unadjusted for body mass index (BMI). After adjustment for BMI, it was no longer significant but the trend remained. The incidence of metabolic syndrome in the NFHL study was higher with increasing viral load, higher BMI, higher trunk-to-limb fat ratio, and Kaletra (lopinavir/ritonavir) or didanosine (ddI) use and lower among college-educated persons. CONCLUSIONS: Metabolic syndrome is mostly diagnosed through low HDL and high triglycerides in HIV. The risk of developing the syndrome is related to HIV, specific medications, and body fat.

Adult↗

PubMed2006

Micronutrient levels and HIV disease status in HIV-infected patients on highly active antiretroviral therapy in the Nutrition for Healthy Living cohort.

BACKGROUND: Low serum micronutrient levels were common before widespread use of highly active antiretroviral therapy (HAART) and were associated with adverse outcomes. Few data are available on micronutrient levels in subjects taking HAART. OBJECTIVE: To determine the prevalence of low serum retinol, alpha-tocopherol, zinc, and selenium in HIV-infected subjects taking HAART and to assess the association of micronutrient levels with HIV disease status. DESIGN: Cross-sectional. SETTING: Nutrition for Healthy Living (NFHL) study. PARTICIPANTS: HIV-infected subjects on HAART. METHODS: Retinol, alpha-tocopherol, zinc, and selenium were determined in frozen serum samples from 171 men and 117 women. Low serum levels were defined as retinol <30 microg/dL, selenium <85 microg/L, alpha-tocopherol <500 microg/dL, and zinc <670 microg/L. Association of micronutrient quartiles with CD4 cell count, CD4 count <200 cells/mm, HIV viral load (VL), and undetectable VL was assessed using adjusted multivariate regression. RESULTS: Five percent of men and 14% of women had low retinol, 8% of men and 3% of women had low selenium, and 7% of men and no women had low alpha-tocopherol. Forty percent of men and 36% of women had low zinc, however. Subjects in the upper quartiles of zinc had lower log VL levels than those in the lowest quartile (significant for women). Subjects in the upper quartiles of selenium also tended to have lower VL levels compared with those in the lowest quartile. Surprisingly, women in the upper quartiles of retinol had higher log VLs than those in the lowest quartile. There was no significant association of any micronutrient with CD4 cell count or likelihood of CD4 count <200 cells/mm. The level of CD4 cell count influenced the association of retinol with log VL in men, however. In men with CD4 counts >350 cells/mm, those with higher retinol had higher log VLs compared with the lowest quartile, whereas in men with CD4 counts <350, those with higher retinol levels had lower log VLs compared with the lowest quartile. CONCLUSIONS: Low retinol, alpha-tocopherol, and selenium are uncommon in HIV-infected subjects on HAART. Zinc deficiency remains common, however. Decreased retinol levels in women and in men with CD4 counts >350 cells/mm and increased zinc and selenium levels in both genders may be associated with improved virologic control.

Adult↗

PubMed2006

Intake of the major carotenoids and the risk of epithelial ovarian cancer in a pooled analysis of 10 cohort studies.

Carotenoids, found in fruits and vegetables, have the potential to protect against cancer because of their properties, including their functions as precursors to vitamin A and as antioxidants. We examined the associations between intakes of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and lycopene and the risk of invasive epithelial ovarian cancer. The primary data from 10 prospective cohort studies in North America and Europe were analyzed and then pooled. Carotenoid intakes were estimated from a validated food frequency questionnaire administered at baseline in each study. Study-specific relative risks (RR) were estimated using the Cox proportional hazards model and then combined using a random-effects model. Among 521,911 women, 2,012 cases of ovarian cancer occurred during a follow-up of 7-22 years across studies. The major carotenoids were not significantly associated with the risk of ovarian cancer. The pooled multivariate RRs (95% confidence intervals) were 1.00 (0.95-1.05) for a 600 microg/day increase in alpha-carotene intake, 0.96 (0.93-1.03) for a 2,500 microg/day increase in beta-carotene intake, 0.99 (0.97-1.02) for a 100 microg/day increase in beta-cryptoxanthin intake, 0.98 (0.94-1.03) for a 2,500 microg/day increase in lutein/zeaxanthin intake and 1.01 (0.97-1.05) for a 4,000 microg/day increase in lycopene intake. These associations did not appreciably differ by study (p-values, tests for between-studies heterogeneity >0.17). Also, the observed associations did not vary substantially by subgroups of the population or by histological type of ovarian cancer. These results suggest that consumption of the major carotenoids during adulthood does not play a major role in the incidence of ovarian cancer.

Breast Neoplasms↗

PubMed2006

Work characteristics and incidence of type 2 diabetes in women.

The authors prospectively investigated associations between potentially stressful work characteristics and type 2 diabetes incidence in 62,574 young and middle-aged women, aged 29-46 years at baseline in 1993, from the Nurses' Health Study II; 365 cases of type 2 diabetes accrued over 6 years of follow-up. Cox proportional hazards regression was used to simultaneously evaluate associations of hours per week in paid employment, years of rotating night-shift work, and job strain with incidence of type 2 diabetes. In multivariate-adjusted analyses, women working less than 20 hours per week had a lower risk of diabetes (relative risk = 0.80, 95% confidence interval: 0.50, 1.30), and those working overtime (> or =41 hours/week) had an elevated risk of diabetes (relative risk = 1.23, 95% confidence interval: 0.98, 1.55) compared with women working 21-40 hours/week (referent) in paid employment (p(trend) = 0.03). In subsequent analysis, the elevated association appeared stronger in unmarried women (p(interaction) = 0.02). A positive association between years in rotating night-shift work and diabetes was mediated entirely by body weight. Job strain was unrelated to risk of type 2 diabetes. In conclusion, working overtime predicted a slightly elevated risk of type 2 diabetes in young and middle-aged female nurses.

Adult↗

PubMed2006

Endogenous steroid hormone concentrations and risk of breast cancer among premenopausal women.

BACKGROUND: Higher levels of endogenous sex steroid hormones are associated with increased risks of breast cancer in postmenopausal women. Data for premenopausal women are sparse, in part because of the complexity of measuring hormone levels that vary cyclically. We prospectively evaluated associations between plasma sex hormone levels and breast cancer risk among premenopausal women in a case-control study nested within the Nurses' Health Study II. METHODS: From 1996 to 1999, blood samples were collected from 18,521 premenopausal women during the early follicular and midluteal phases of their menstrual cycles. A total of 197 cases of breast cancer were diagnosed among these women after blood collection and before June 1, 2003; these case subjects were matched to 394 control subjects. Logistic regression models, controlling for breast cancer risk factors, were used to calculate relative risks (RRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: Women in the highest (versus the lowest) quartiles of follicular total and free estradiol levels had statistically significantly increased risks of breast cancer (RR = 2.1 [95% CI = 1.1 to 4.1], P(trend) = .08, and RR = 2.4 [95% CI = 1.3 to 4.5], P(trend) = .01, respectively); the associations were stronger for invasive breast cancer and for estrogen and progesterone receptor-positive (ER+/PR+) tumors. Luteal estradiol levels were not associated with breast cancer risk. Higher levels of total and free testosterone and androstenedione in both menstrual cycle phases were associated with modest, non-statistically significant increases in overall risk of breast cancer and with stronger, statistically significant increases in risks of invasive and ER+/PR+ cancers (e.g., RR of invasive cancers for the top [versus bottom] quartile of luteal total testosterone levels = 2.0 [95% CI = 1.1 to 3.6], P(trend) = .05, and RR of ER+/PR+ cancers = 2.9 [95% CI = 1.4 to 6.0], P(trend) = .02). Levels of estrone, estrone sulfate, progesterone, and sex hormone-binding globulin were not associated with breast cancer risk. The absolute number of cases observed over 3 years were 30 among women in the lowest 25% of follicular total estradiol levels and 50 among women in the highest 25%. CONCLUSIONS: Levels of circulating estrogens and androgens may be important in the etiology of premenopausal breast cancer.

Adult↗

PubMed2006

Milk consumption and acne in adolescent girls.

There has been a remarkable paucity of evidence for an association between diet and acne. Our previous studies suggest that there is an association between milk intake and teenage acne. This is a prospective cohort study to evaluate that relationship. We studied 6,094 girls, aged 9-15 years in 1996, who reported dietary intake on up to three food frequency questionnaires from 1996 to 1998. Presence and severity of acne was assessed by questionnaire in 1999. We computed multivariate prevalence ratios (PR) and 95 percent confidence intervals for acne. After accounting for age at baseline, height and energy intake, the multivariate PRs (95 % CI; p-value for test of trend) for acne comparing highest (2 or more servings per day) to lowest (<1 per week) intake categories in 1996, were 1.20 (1.09, 1.31; <0.001) for total milk, 1.19 (1.06, 1.32; <0.001) for whole milk, 1.17 (1.04, 1.31; 0.002) for low fat milk and 1.19 (1.08, 1.31; <0.001) for skim milk. This result did not change appreciably when we excluded girls who reported use of contraceptives and when we restricted our analysis to those younger than 11 years of age at baseline. We found a positive association between intake of milk and acne. This finding supports earlier studies and suggests that the metabolic effects of milk are sufficient to elicit biological responses in consumers.

Acne Vulgaris↗

PubMed2006

Methods for pooling results of epidemiologic studies: the Pooling Project of Prospective Studies of Diet and Cancer.

With the growing number of epidemiologic publications on the relation between dietary factors and cancer risk, pooled analyses that summarize results from multiple studies are becoming more common. Here, the authors describe the methods being used to summarize data on diet-cancer associations within the ongoing Pooling Project of Prospective Studies of Diet and Cancer, begun in 1991. In the Pooling Project, the primary data from prospective cohort studies meeting prespecified inclusion criteria are analyzed using standardized criteria for modeling of exposure, confounding, and outcome variables. In addition to evaluating main exposure-disease associations, analyses are also conducted to evaluate whether exposure-disease associations are modified by other dietary and nondietary factors or vary among population subgroups or particular cancer subtypes. Study-specific relative risks are calculated using the Cox proportional hazards model and then pooled using a random- or mixed-effects model. The study-specific estimates are weighted by the inverse of their variances in forming summary estimates. Most of the methods used in the Pooling Project may be adapted for examining associations with dietary and nondietary factors in pooled analyses of case-control studies or case-control and cohort studies combined.

Diet↗

PubMed2006

Natural hair color and the incidence of endometriosis.

OBJECTIVE: To investigate a previously hypothesized relation between natural hair color and endometriosis. DESIGN: Prospective cohort study. SETTING: Nurses' Health Study II with 10 years of follow-up. PARTICIPANT(S): A total of 90,065 women, 25-42 years old, who had never been diagnosed with endometriosis, infertility, or cancer at baseline in 1989. MAIN OUTCOME MEASURE(S): Incidence of laparoscopically confirmed endometriosis according to natural hair color. RESULT(S): During 379,422 person-years of follow-up, 1,130 cases of laparoscopically confirmed endometriosis were reported among women with no past infertility. After adjusting for age, calendar time, parity, race, and body mass index at age 18, we observed no association overall. However, compared with women with any other hair color, we observed an increased rate of endometriosis among women with naturally red hair who had never been infertile (incidence rate = 1.3, 95% confidence interval [CI] = 1.0-1.7), but a decreased rate among women with naturally red hair among women who were infertile (incidence rate = 0.4, 95% CI = 0.2-1.2); P value, test for heterogeneity = .03. CONCLUSION(S): Overall, we did not observe a significant relation between red hair color and the rate of endometriosis, however this prospective cohort study suggests that the relation may differ by infertility status.

Adult↗

PubMed2006

Intakes of vitamins A, C and E and folate and multivitamins and lung cancer: a pooled analysis of 8 prospective studies.

Intakes of vitamins A, C and E and folate have been hypothesized to reduce lung cancer risk. We examined these associations in a pooled analysis of the primary data from 8 prospective studies from North America and Europe. Baseline vitamin intake was assessed using a validated food-frequency questionnaire, in each study. We calculated study-specific associations and pooled them using a random-effects model. During follow-up of 430,281 persons over a maximum of 6-16 years in the studies, 3,206 incident lung cancer cases were documented. Vitamin intakes were inversely associated with lung cancer risk in age-adjusted analyses; the associations were greatly attenuated after adjusting for smoking and other risk factors for lung cancer. The pooled multivariate relative risks, comparing the highest vs. lowest quintile of intake from food-only, were 0.96 (95% confidence interval (CI) 0.83-1.11) for vitamin A, 0.80 (95% CI 0.71-0.91) for vitamin C, 0.86 (95% CI 0.76-0.99) for vitamin E and 0.88 (95% CI 0.74-1.04) for folate. The association with vitamin C was not independent of our previously reported inverse association with beta-cryptoxanthin. Further, vitamin intakes from foods plus supplements were not associated with a reduced risk of lung cancer in multivariate analyses, and use of multivitamins and specific vitamin supplements was not significantly associated with lung cancer risk. The results generally did not differ across studies or by sex, smoking habits and lung cancer cell type. In conclusion, these data do not support the hypothesis that intakes of vitamins A, C and E and folate reduce lung cancer risk.

Antioxidants↗

PubMed2006

Association of indoor nitrogen dioxide with respiratory symptoms in children: application of measurement error correction techniques to utilize data from multiple surrogates.

In 1991, Neas et al. reported that indoor nitrogen dioxide (NO(2)), a byproduct of high-temperature combustion, was significantly associated with lower respiratory symptoms among a cohort of 1,159 white children aged 7-11 years in six US cities studied from 1983 to 1988. For each 15 p.p.b. increment of NO(2), the multivariate adjusted odds ratio (OR) was 1.4 (95% confidence interval (CI)=[1.1, 1.7]). Although indoor NO(2) concentration in the ambient air was assessed only in a subset of the children, the prevalence of lower respiratory symptoms and surrogate exposure variables were available in all of the children at the time of the indoor monitoring program. This paper evaluates the effect of indoor NO(2) exposure on the annual risk of lower respiratory symptoms by applying a regression calibration method to the 2,891 children in the overall study with complete covariate and outcome data, 1,137 of whom had NO(2) directly measured and 1,754 of whom only surrogate exposure data were available. An estimate of the indoor annual NO(2) exposure effect (p.p.b.) is obtained, which is adjusted for measurement error induced by the use of surrogate NO(2) sources among the 1,754. These sources include the presence of a gas stove with or without a pilot light, the presence of a kerosene space heater, the presence of a wood stove, and the usage of a stove for heating, and residential characteristics, including fan usage for kitchen ventilation and the total number of rooms in the home. After adjusting for age, gender, city, parental history of respiratory diseases, and smoking inside the children's home (packs/day), a 15-p.p.b. increment in NO(2) exposure was found to be associated with a significant 50% increased annual risk of lower respiratory symptoms (OR=1.5, 95% CI=[1.2, 1.8]). Simulation results indicated that, under conditions similar to those observed in these data, the estimator is unbiased and has a coverage probability close to the nominal value. Using the methodology illustrated in this paper, it became possible to utilize all data available and obtain a 34% more precise estimate of the NO(2) exposure effect on lower respiratory symptoms, which was adjusted for measurement error due to using NO(2) surrogates instead of directly measured NO(2).

Air Pollution, Indoor↗

PubMed2006

Quantifying bias due to allele misclassification in case-control studies of haplotypes.

OBJECTIVES: Genotyping errors can induce biases in frequency estimates for haplotypes of single nucleotide polymorphisms (SNPs). Here, we considered the impact of SNP allele misclassification on haplotype odds ratio estimates from case-control studies of unrelated individuals. METHODS: We calculated bias analytically, using the haplotype counts expected in cases and controls under genotype misclassification. We evaluated the bias due to allele misclassification across a range of haplotype distributions using empirical haplotype frequencies within blocks of limited haplotype diversity. We also considered simple two- and three-locus haplotype distributions to understand the impact of haplotype frequency and number of SNPs on misclassification bias. RESULTS: We found that for common haplotypes (>5% frequency), realistic genotyping error rates (0.1-1% chance of miscalling an allele), and moderate relative risks (2-4), the bias was always towards the null and increases in magnitude with increasing error rate, increasing odds ratio. For common haplotypes, bias generally increased with increasing haplotype frequency, while for rare haplotypes, bias generally increased with decreasing frequency. When the chance of miscalling an allele is 0.5%, the median bias in haplotype-specific odds ratios for common haplotypes was generally small (<4% on the log odds ratio scale), but the bias for some individual haplotypes was larger (10-20%). Bias towards the null leads to a loss in power; the relative efficiency using a test statistic based upon misclassified haplotype data compared to a test based on the unobserved true haplotypes ranged from roughly 60% to 80%, and worsened with increasing haplotype frequency. CONCLUSIONS: The cumulative effect of small allele-calling errors across multiple loci can induce noticeable bias and reduce power in realistic scenarios. This has implications for the design of candidate gene association studies that utilize multi-marker haplotypes.

Alleles↗

PubMed2006

A pooled analysis of 12 cohort studies of dietary fat, cholesterol and egg intake and ovarian cancer.

Fat and cholesterol are theorized to promote ovarian carcinogenesis by increasing circulating estrogen levels. Although case-control studies have reported positive associations between total and saturated fat intake and ovarian cancer risk, two cohort studies have observed null associations. Dietary cholesterol and eggs have been positively associated with ovarian cancer risk. A pooled analysis was conducted on 12 cohort studies. Among 523,217 women, 2,132 incident epithelial ovarian cancer cases were identified. Study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated by Cox proportional hazards models, and then pooled using a random effects model. Total fat intake was not associated with ovarian cancer risk (pooled multivariate RR = 1.08, 95% CI 0.86-1.34 comparing > or =45 to 30-<35% of calories). No association was observed for monounsaturated, polyunsaturated, trans-unsaturated, animal and vegetable fat, cholesterol and egg intakes with ovarian cancer risk. A weakly positive, but non-linear association, was observed for saturated fat intake (pooled multivariate RR = 1.29, 95% CI: 1.01-1.66 comparing highest versus lowest decile). Results for histologic subtypes were similar. Overall, fat, cholesterol and egg intakes were not associated with ovarian cancer risk. The positive association for saturated fat intake at very high intakes merits further investigation.

Cholesterol↗

PubMed2006

Comparison of bioelectrical impedance and BMI in predicting obesity-related medical conditions.

OBJECTIVE: To determine the relative validity of specific bioelectrical impedance analysis (BIA) prediction equations and BMI as predictors of physiologically relevant general adiposity. RESEARCH METHODS AND PROCEDURES: Subjects were >12,000 men and women from the Third National Health and Nutrition Examination Survey population. We examined the correlations between BMI and percentage body fat based on 51 different predictive equations, blood pressure, and blood levels of glucose, high-density lipoprotein cholesterol, and triglycerides, which are known to reflect adiposity, while controlling for other determinants of these physiological measures. RESULTS: BMI consistently had one of the highest correlations across biological markers, and no BIA-based measure was superior. Percent body fat estimated from BIA was minimally predictive of the physiological markers independent of BMI. DISCUSSION: These results suggest that BIA is not superior to BMI as a predictor of overall adiposity in a general population.

Adult↗

PubMed2006

Trends in obesity, underweight, and wasting among women attending prenatal clinics in urban Tanzania, 1995-2004.

BACKGROUND: Many developing countries are currently burdened by both undernutrition and increasing rates of overweight and obesity. Scarce data are available from population studies on the recent trends and current epidemiology of obesity in African settings. OBJECTIVES: The objectives were to evaluate changes in the prevalence of obesity, underweight, and wasting in women of reproductive age from Dar es Salaam, Tanzania, during the past 10 y and to identify contemporary sociodemographic correlates of these indicators. DESIGN: We estimated the prevalence of obesity [body mass index (BMI; in kg/m2) > or = 30], underweight (BMI < 18.5), and wasting (midupper arm circumference < 22 cm) in 73 689 women aged 14-52 y who attended antenatal care clinics in the city of Dar es Salaam, Tanzania, between 1995 and 2004. RESULTS: The prevalence of obesity rose steadily and progressively from 3.6% in 1995 to 9.1% in 2004 [adjusted prevalence ratio (PR): 1.97; 95% CI: 1.66, 2.33; P for trend for year < 0.0001]. Underweight showed only a modest decline from 3.3% in 1995 to 2.6% in 2004 (adjusted PR: 0.91; 95% CI: 0.75, 1.10; P for trend for year = 0.003), whereas no change was observed in the prevalence of wasting. In the most recent years (2003 and 2004), obesity was positively associated with age, parity, and socioeconomic status and inversely with HIV infection. Underweight was inversely related to socioeconomic status and positively to HIV status. CONCLUSION: The recent, rapid, and large increase in the prevalence of obesity in women represents a new competing public health priority in urban Tanzania, where underweight and wasting have not decreased substantially.

Adolescent↗

PubMed2006

Dairy products and ovarian cancer: a pooled analysis of 12 cohort studies.

BACKGROUND: Dairy foods and their constituents (lactose and calcium) have been hypothesized to promote ovarian carcinogenesis. Although case-control studies have reported conflicting results for dairy foods and lactose, several cohort studies have shown positive associations between skim milk, lactose, and ovarian cancer. METHODS: A pooled analysis of the primary data from 12 prospective cohort studies was conducted. The study population consisted of 553,217 women among whom 2,132 epithelial ovarian cases were identified. Study-specific relative risks and 95% confidence intervals were calculated by Cox proportional hazards models and then pooled by a random-effects model. RESULTS: No statistically significant associations were observed between intakes of milk, cheese, yogurt, ice cream, and dietary and total calcium intake and risk of ovarian cancer. Higher lactose intakes comparing > or = 30 versus <10 g/d were associated with a statistically significant higher risk of ovarian cancer, although the trend was not statistically significant (pooled multivariate relative risk, 1.19; 95% confidence interval, 1.01-1.40; P(trend) = 0.19). Associations for endometrioid, mucinous, and serous ovarian cancer were similar to the overall findings. DISCUSSION: Overall, no associations were observed for intakes of specific dairy foods or calcium and ovarian cancer risk. A modest elevation in the risk of ovarian cancer was seen for lactose intake at the level that was equivalent to three or more servings of milk per day. Because a new dietary guideline recommends two to three servings of dairy products per day, the relation between dairy product consumption and ovarian cancer risk at these consumption levels deserves further examination.

Calcium, Dietary↗

PubMed2006

Reproducibility of plasma steroid hormones, prolactin, and insulin-like growth factor levels among premenopausal women over a 2- to 3-year period.

Few studies have evaluated whether a single blood hormone measurement, as is available in most epidemiologic studies, sufficiently characterizes a premenopausal woman's long-term hormone levels; there is particular concern whether sex steroid hormones, which fluctuate during the menstrual cycle, are reliable. We conducted a prospective study within the Nurses' Health Study II to examine the reproducibility of plasma estrogens, androgens, progesterone, prolactin, sex hormone binding globulin, insulin-like growth factor-I (IGF-I), and IGF binding protein-3 (IGFBP-3). One blood sample per year over 3 years was collected from 113 premenopausal women during both the follicular and luteal phases of the menstrual cycle. We calculated intraclass correlation coefficients (ICC) across the three samples for all women. Among estrogens, ICCs ranged from 0.38 (estradiol) to 0.60 (estrone sulfate) in the follicular phase and from 0.44 (estrone) to 0.69 (estrone sulfate) in the luteal phase. Among androgens, ICCs ranged from 0.58 (androstenedione) to 0.94 [dehydroepiandrostenedione sulfate (DHEAS)] in the follicular phase and from 0.56 (testosterone) to 0.81 (DHEAS) in the luteal phase. When values were averaged across the follicular and luteal phases, the ICC for prolactin was 0.64 whereas ICCs for IGF-I and IGFBP-3 were 0.86 and 0.82, respectively. The ICC for progesterone in the luteal phase was only 0.29. These data suggest that for androgens, estrone sulfate, prolactin, IGF-I, and IGFBP-3, a single measurement can reliably categorize average levels over at least a 3-year period in premenopausal women. For estrone and estradiol, where ICCs were relatively low, it is important to use reproducibility data such as those to correct for measurement error in epidemiologic studies.

Adult↗