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F J Nieto

Publications and source records attributed to F J Nieto.

At least 55 records · Page 3Linked to original sources
PubMed1999

Chlamydia pneumoniae infection and incident coronary heart disease: the Atherosclerosis Risk in Communities Study.

Pathologic findings and cross-sectional epidemiologic studies suggest that past infection with Chlamydia pneumoniae is associated with clinical and subclinical atherosclerotic disease, although evidence from prospective studies is still scarce. The association between chronic infection by C. pneumoniae and incident coronary heart disease (CHD) was investigated in a case-cohort study conducted among participants in the Atherosclerosis Risk in Communities Study who were free of CHD at the baseline examination (1986-1989). Levels of C. pneumoniae immunoglobulin G (IgG) antibodies in serum collected at baseline from 246 incident cases of CHD identified during follow-up (median, 3.3 years; maximum, 5 years) were compared with those from a stratified sample of the baseline cohort (n = 550). Among incident CHD cases, 65% had IgG antibody titers > or =1:64, compared with 55% of noncases (compared with negative IgG titers, the relative hazard of CHD was 1.6 (p < 0.01)). In multivariate analyses controlling for other risk factors (age, gender, smoking, serum cholesterol, hypertension, diabetes mellitus, and educational level), the above estimates were substantially reduced and became statistically nonsignificant (relative hazard = 1.2). A significantly increased CHD hazard associated with IgG antibody titers > or =1:64 was observed among nonsmokers, even after adjustment for other risk factors. Overall, these results do not provide strong support for the hypothesis that C. pneumoniae infection is a risk factor for clinical CHD. Studies with longer follow-up periods will be necessary to determine whether C. pneumoniae infection is involved as an etiologic factor in earlier phases of atherogenesis.

Antibodies, Bacterial↗
PubMed1999

Pancreatic cancer risk and nutrition-related methyl-group availability indicators in male smokers.

BACKGROUND: Few risk factors for pancreatic cancer have been identified, with age and cigarette smoking being the most consistent. The protective effect associated with consumption of fruits and vegetables-the major dietary sources of folate-is suggestive of a role for factors influencing cellular methylation reactions; however, to our knowledge, no study has investigated this relationship. Whether biochemical indicators of methyl-group availability are associated with exocrine pancreatic cancer risk was the focus of this investigation. METHODS: We conducted a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of 29133 male Finnish smokers aged 50-69 years. One hundred twenty-six subjects with incident exocrine pancreatic cancer were matched by date of baseline blood draw (+/-30 days), study center, age (+/-5 years), trial intervention group, and completion of dietary history to 247 control subjects, who were alive and free from cancer at the time the case subjects were diagnosed. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined by use of conditional logistic regression. Reported P values are two-tailed. RESULTS: Serum folate and pyridoxal-5'-phosphate (PLP) concentrations showed statistically significant inverse dose-response relationships with pancreatic cancer risk, with the highest serum tertiles having approximately half the risk of the lowest (folate: OR = 0.45; 95% CI = 0.24-0.82; P for trend = .009, and PLP: OR = 0.48; 95% CI = 0.26-0.88; P for trend = .02). An increased pancreatic cancer risk was also observed with greater exposure to cigarettes (e.g., pack-years [number of packs smoked per day x number of years of smoking], highest versus lowest quartile: OR = 2.13; 95% CI = 1.13-3.99; P for trend = .04). CONCLUSIONS: These results support the hypothesis that maintaining adequate folate and pyridoxine status may reduce the risk of pancreatic cancer and confirm the risk previously associated with cigarette smoking.

Aged↗
PubMed1999

Estimates of animal and plant protein intake in US adults: results from the Third National Health and Nutrition Examination Survey, 1988-1991.

OBJECTIVE: To describe the sources of protein intake in a sample of the US adult population and among subgroups defined by race-ethnicity, age, and gender. DESIGN: The Third National Health and Nutrition Examination Survey, 1988-1991, is a stratified random sample of the total civilian noninstitutionalized population, drawn from the 50 United States and the District of Columbia. For all foods consumed by the participants, based on a 24-hour dietary recall, protein sources and the contribution of each protein type to the total protein intake were determined. SUBJECTS: Adult participants in the third National Health and Nutrition Examination Survey (n = 7,924). STATISTICAL ANALYSES: Weighted total, age-specific, and age-adjusted mean protein intakes were calculated using SAS and WesVarPC. Statistical differences were determined by 2-tailed t tests. RESULTS: The main protein source in the American diet is animal protein (69%). Meat, fish, and poultry protein combined contributed the most to animal protein (42%), followed by dairy protein (20%). Grains (18%) contributed the most to plant protein consumption. Women consumed a lower percentage of beef (14%) and pork (7%) protein than did men (18% and 9%, respectively). Women also consumed a higher percentage of poultry (13%), dairy (22%), and fruit and vegetable (11%) protein than did men (11%, 19%, and 9%, respectively). Blacks reported eating a higher percentage of poultry (18%) and pork (11%) protein and a lower percent of dairy protein (14%) than did whites (12%, 7%, and 22%, respectively) and Mexican-Americans (11%, 8%, and 17%, respectively). Mexican-Americans consumed a higher percentage of legume (7%) and egg (7%) protein than did whites (4% and 4%, respectively) and blacks (4% and 5%, respectively). Whites consumed a higher percentage of grain protein (19%) than did blacks (16%) and Mexican-Americans (15%). CONCLUSIONS: These results show that, although the percentage of total energy from protein may be similar among race-ethnicities and between men and women, their sources of protein are different. These differences should be taken into account when providing nutrition education for specific populations.

Adult↗
PubMed1999

Short- and long-term prediction of clinical and subclinical atherosclerosis by traditional risk factors.

This study compares the cross-sectional and longitudinal associations of cardiovascular risk factors with clinical coronary heart disease (CHD) and with subclinical carotid atherosclerosis measured by ultrasound. The study population were 1410 participants in the Atherosclerotic Risk in Community (ARIC) Study (1987-1989) who also participated in a 1974 community health survey. Smoking in 1974 was associated with increased CHD prevalence in 1987-1989 (adjusted prevalence ratio = 2.2), whereas the corresponding cross-sectional association was practically absent. For hypercholesterolemia and hypertension, the longitudinal associations with CHD were also stronger than the cross-sectional associations. In contrast, the strength of the longitudinal and cross-sectional associations with carotid atherosclerosis was generally similar. These results underscore the advantages of using subclinical measures of atherosclerosis in cross-sectional studies. In addition, they suggest that the presence of smoking, hypertension, or hypercholesterolemia in mid-adulthood may have some persisting effects on the development of atherosclerotic disease in later life.

Adult↗
PubMed1999

Estimating the magnitude of close-up work in school-age children: a comparison of questionnaire and diary instruments.

BACKGROUND: Numerous scientists have noted a relationship between close-up work and myopia. METHODS: A questionnaire and four 24-hour diaries were developed to estimate close-up work activity in a cohort study of close-up work and myopia progression in Singapore children. The number of hours per day that children engaged in each type of close-up work activity over a weekday and weekend during the school term, during the examination period, and in the vacation were estimated. RESULTS: The children spent an average of 6.6 hours per day on total weighted average close-up work, of which 4.3 hours were spent on reading and writing. The intra-class correlation coefficient for the reproducibility of the questionnaire was 0.87 (95% CI 0.85-0.91). The intra-class correlation coefficient for total weighted close-up work was 0.50 (95% CI 0.34-0.66) when the questionnaire was compared with the four 24-hour diaries. The amount of close-up work activity increased with age. CONCLUSIONS: A questionnaire for close-up work was developed and proven to be reproducible and comparable to four 24-hour diaries.

Activities of Daily Living↗
PubMed1999

Distance, lighting, and parental beliefs: understanding near work in epidemiologic studies of myopia.

PURPOSE: To develop measures and indices of factors (distance of eye from object, posture, and lighting) that may modify a possible effect of near work activity on myopia. METHODS: The duration of near work, the distance of an object from eye, lighting conditions, and other sociodemographic characteristics were asked in an interview. Both distance and lighting information from the questionnaire were compared with more precise measurements. RESULTS: Diopter hours were quantified as the duration of near work multiplied by the reciprocal of the distance which the activity was performed. The intraclass correlation coefficient of the reliability of distance information for each type of near work activity ranged from 0.43 to 0.91. Home light meter readings were significantly higher for children who were reading under both room and reading light, and the distances from the questionnaire were comparable to the measured distances. CONCLUSIONS: Measures of posture, distance, and lighting factors have been developed to study the possible effect modifiers of the effects of near work on myopia.

Accommodation, Ocular↗
PubMed1999

Neighbourhood differences in diet: the Atherosclerosis Risk in Communities (ARIC) Study.

STUDY OBJECTIVE: To investigate whether neighbourhood characteristics are related to dietary patterns independently of individual level variables. DESIGN: A cross sectional analysis of the relation between neighbourhood median household income and food and nutrient intakes, before and after adjustment for individual level variables. SETTING: Four United States communities (Washington Co, MD; Suburban Minneapolis, MN; Forsyth Co, NC, and Jackson, MS). PARTICIPANTS: 13,095 adults aged 45 to 64 years participating in the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study, a prospective study of atherosclerosis. MEASUREMENTS AND MAIN RESULTS: Information on diet and individual level income was obtained from the baseline examination of the ARIC Study. Diet was assessed using a semi-quantitative food frequency questionnaire. Information on neighbourhood (census defined block groups) median household income was obtained from the 1990 US Census. Multilevel models were used to account for the multilevel structure of the data. Living in lower income neighbourhoods was generally associated with decreased energy adjusted intake of fruits, vegetables, fish, and increased intake of meat. Patterns generally persisted after adjustment for individual level income, but were often not statistically significant. Inconsistent associations were recorded for the intake of saturated fat, polyunsaturated fat, and cholesterol. Overall, individual level income was a more consistent predictor of diet than neighbourhood income. CONCLUSION: Despite limitations in the definition and characterisation of neighbourhoods, this study found consistent (albeit small) differences across neighbourhoods in food intake, suggesting that more in depth research into potential neighbourhood level determinants of diet is warranted.

Arteriosclerosis↗
PubMed1999

Relation of sleepiness to respiratory disturbance index: the Sleep Heart Health Study.

Obstructive sleep apnea syndrome is a well recognized cause of excessive sleepiness; however, the relation of sleepiness to mild sleep-disordered breathing (SDB), which affects as much as half the adult population, is uncertain. In order to explore this relation, we conducted a cross-sectional cohort study of community-dwelling adults participating in the Sleep Heart Health Study, a longitudinal study of the cardiovascular consequences of SDB. The study sample comprises 886 men and 938 women, with a mean age of 65 (SD 11) yr. Sleepiness was quantified using the Epworth Sleepiness Scale (ESS). Sleep-disordered breathing was quantified by the respiratory disturbance index (RDI), defined as the number of apneas plus hypopneas per hour of sleep, measured during in-home polysomnography. When RDI was categorized into four groups (< 5, 5 to < 15, 15 to < 30, >/= 30), a significantly progressive increase in mean ESS score was seen across all four levels of SDB, from 7.2 (4.3) in subjects with RDI < 5 to 9.3 (4.9) in subjects with RDI >/= 30 (p < 0.001). There was no significant modification of this effect by age, sex, body mass index, or evidence of chronic restriction of sleep time or periodic limb movement disorder. The percentage of subjects with excessive sleepiness, defined as an ESS score >/= 11, increased from 21% in subjects with RDI < 5 to 35% in those with RDI >/= 30 (p < 0. 001). We conclude that SDB is associated with excess sleepiness in community-dwelling, middle-aged and older adults, not limited to those with clinically apparent sleep apnea.

Aged↗
PubMed1999

Modeling hypersomnolence in sleep-disordered breathing. A novel approach using survival analysis.

The etiology of excessive daytime sleepiness in patients with sleep-disordered breathing (SDB) is not well defined. In this study, we examined the relationships between several clinical and polysomnographic parameters and the degree of hypersomnolence in 741 patients with SDB (apnea-hypopnea index [AHI] >/= 10 events/h). The study sample was obese (body mass index [BMI]: 35.3 +/- 8.5 kg/m2) and had evidence of moderate SDB (AHI: 47.6 +/- 29.3 events/h). Hypersomnolence was quantified with the multiple sleep latency test (MSLT) and survival analysis was used to assess the risk factors for hypersomnolence. In a multivariate proportional hazards model, AHI and nocturnal hypoxemia were independent predictors of hypersomnolence (MSLT < 10 min). The adjusted relative risks (RR) of hypersomnolence were 1.00, 1.30, and 1.65 for patients with an AHI of 10 to 29.9, 30 to 59.9, and >/= 60 events/h, respectively. A positive association between hypersomnolence and oxyhemoglobin desaturation (DeltaSaO2) was observed with RR of 1.00, 1.18, 1.43, and 1.94 for a DeltaSaO2 of </= 5%, 5.1 to 10%, 10.1 to 15%, and > 15%, respectively. Sleep fragmentation, as assessed by the distribution of sleep stages, was also an independent predictor of hypersomnolence. Using stage 1 sleep as a reference, an increase in stage 2 and slow wave sleep (SWS) were protective from hypersomnolence. For a 10% increase in stage 2 or SWS the adjusted RR for hypersomnolence were 0.93 and 0.79, respectively. REM sleep showed no significant association with the degree of hypersomnolence. These results suggest that AHI, nocturnal hypoxemia, and sleep fragmentation are independent determinants of hypersomnolence in SDB.

Adult↗
PubMed1999

Blood cholesterol and apolipoprotein B levels in relation to intakes of animal and plant proteins in US adults.

Few studies have examined the association between specific sources of protein and blood lipids in a national sample of adults. We examined this relationship in a sample of adults 20 years and older who participated in phase 1 (1988-91) of the Third National Health and Nutrition Examination Survey, a representative sample of the United States non-institutionalized population. After excluding those participants who reported having been told they had high blood cholesterol concentrations, the final sample size was 6228. Mean intakes of different sources of proteins, as a percentage of total protein, were compared in quartiles of blood lipids. Intakes were adjusted for age, sex and race. Additional adjustments were made for other dietary variables, recall day, BMI, smoking, and income. We observed a lower percentage meat, fish and poultry (MFP) protein intake, including a lower percentage of beef and pork protein, among persons in the lowest quartile of serum total cholesterol and apolipoprotein B (ApoB) concentrations than among persons in the higher quartiles. The percentage of plant protein intake was higher in the lowest quartile than in the highest quartile of serum cholesterol. We also observed a higher percentage of fruit protein intake with lower serum cholesterol and ApoB concentrations. We conclude that in this cross-sectional sample, consumption of MFP proteins was consistently higher among persons with higher cholesterol concentrations while consumption of plant proteins was consistently higher among persons with lower cholesterol concentrations. Our findings support the importance of assessing intake of specific protein sources, especially in studies that address dietary intake in relation to blood lipids.

Adult↗
PubMed1998

Reliability of scoring respiratory disturbance indices and sleep staging.

STUDY OBJECTIVES: Unattended, home-based polysomnography (PSG) is increasingly used in both research and clinical settings as an alternative to traditional laboratory-based studies, although the reliability of the scoring of these studies has not been described. The purpose of this study is to describe the reliability of the PSG scoring in the Sleep Heart Health Study (SHHS), a multicenter study of the relation between sleep-disordered breathing measured by unattended, in-home PSG using a portable sleep monitor, and cardiovascular outcomes. DESIGN: The reliability of SHHS scorers was evaluated based on 20 randomly selected studies per scorer, assessing both interscorer and intrascorer reliability. RESULTS: Both inter- and intrascorer comparisons on epoch-by-epoch sleep staging showed excellent reliability (kappa statistics >0.80), with stage 1 having the greatest discrepancies in scoring and stage 3/4 being the most reliably discriminated. The arousal index (number of arousals per hour of sleep) was moderately reliable, with an intraclass correlation (ICC) of 0.54. The scorers were highly reliable on various respiratory disturbance indices (RDIs), which incorporate an associated oxygen desaturation in the definition of respiratory events (2% to 5%) with or without the additional use of associated EEG arousal in the definition of respiratory events (ICC>0.90). When RDI was defined without considering oxygen desaturation or arousals to define respiratory events, the RDI was moderately reliable (ICC=0.74). The additional use of associated EEG arousals, but not oxygen desaturation, in defining respiratory events did little to increase the reliability of the RDI measure (ICC=0.77). CONCLUSIONS: The SHHS achieved a high degree of intrascorer and interscorer reliability for the scoring of sleep stage and RDI in unattended in-home PSG studies.

Humans↗
PubMed1998

Helicobacter pylori seropositivity and coronary heart disease incidence. Atherosclerosis Risk In Communities (ARIC) Study Investigators.

BACKGROUND: Several epidemiological and clinical reports have suggested seropositivity for Helicobacter pylori may be a risk factor for coronary heart disease. However, there has been no prospective study of this association involving an ethnically diverse sample of middle-aged men and women. METHODS AND RESULTS: Using a prospective, case-cohort design, we determined H pylori seropositivity in relation to coronary heart disease incidence over a median follow-up period of 3.3 years among middle-aged men and women. There were 217 incident coronary heart disease cases and a cohort sample of 498. We determined H pylori antibody status by measuring IgG antibody to the high-molecular-weight cell-associated proteins of H pylori using a sensitive and specific ELISA. The prevalence of H pylori seropositivity was higher in blacks than whites, in those with less than high school education, in those with lower plasma pyridoxal 5'-phosphate and higher homocyst(e)ine concentrations, in those who did not use vitamin supplements, in those with higher fibrinogen levels, and in those seropositive for cytomegalovirus and herpes simplex type I (all P<0.05). The age-, sex-, race-, and field center-adjusted hazard ratio of coronary heart disease for H pylori seropositivity was 1.03 (95% CI=0.68 to 1.57). After adjustment for other risk factors, including fibrinogen, cytomegalovirus seropositivity, and herpes simplex type I seropositivity, the hazard ratio was 0.85 (95% CI=0.43 to 1.69). H pylori seropositivity also was not associated with increased mean intima-media thickness of the carotid artery, a measure of subclinical atherosclerosis. CONCLUSIONS: H pylori infection is probably not an important contributor to clinical coronary heart disease events.

Antibodies, Bacterial↗
PubMed1998

Prospective study of coronary heart disease incidence in relation to fasting total homocysteine, related genetic polymorphisms, and B vitamins: the Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND: Elevated plasma total homocysteine (tHcy), low B-vitamin intake, and genetic polymorphisms related to tHcy metabolism may play roles in coronary heart disease (CHD). More prospective studies are needed. METHODS AND RESULTS: We used a prospective case-cohort design to determine whether tHcy-related factors are associated with incidence of CHD over an average of 3.3 years of follow-up in a biracial sample of middle-aged men and women. Age-, race-, and field center-adjusted CHD incidence was associated positively (P<0.05) with tHcy in women but not men, and CHD was associated negatively (P<0.05) with plasma folate (women only), plasma pyridoxal 5'-phosphate (both sexes), and vitamin supplementation (women only). However, after accounting for other risk factors, only plasma pyridoxal 5'-phosphate was associated with CHD incidence; the relative risk for the highest versus lowest quintile of pyridoxal 5'-phosphate was 0.28 (95% CI=0.1 to 0.7). There was no association of CHD with the C677T mutation of the methylenetetrahydrofolate reductase gene or with 3 mutations of the cystathionine beta-synthase gene. CONCLUSIONS: Our prospective findings add uncertainty to conclusions derived mostly from cross-sectional studies that tHcy is a major, independent, causative risk factor for CHD. Our findings point more strongly to the possibility that vitamin B6 offers independent protection. Randomized trials, some of which are under way, are needed to better clarify the interrelationships of tHcy, B vitamins, and cardiovascular disease.

Arteriosclerosis↗
PubMed1998

Cigarette smoking and progression of atherosclerosis: The Atherosclerosis Risk in Communities (ARIC) Study.

CONTEXT: Cigarette smoking is a powerful risk factor for incident heart disease and stroke, but the relationship of active and passive smoking with the progression of atherosclerosis has not been described. OBJECTIVE: To examine the impact of active smoking and exposure to environmental tobacco smoke (ETS) on the progression of atherosclerosis. DESIGN: A longitudinal assessment of the relationship between smoking exposure evaluated at the initial visit and the 3-year change in atherosclerosis. SETTING: A population-based cohort of middle-aged adults from 4 communities in the United States. PARTICIPANTS: A total of 10914 participants from the Atherosclerosis Risk in Communities (ARIC) study enrolled between 1987 and 1989. MAIN OUTCOME MEASURE: Change in atherosclerosis from baseline to the 3-year follow-up as indexed by intimal-medial thickness of the carotid artery assessed by ultrasound and adjusted for demographic characteristics, cardiovascular risk factors, and lifestyle variables. RESULTS: Exposure to cigarette smoke was associated with progression of atherosclerosis. Relative to never smokers and after adjustment for demographic characteristics, cardiovascular risk factors, and lifestyle variables, current cigarette smoking was associated with a 50% increase in the progression of atherosclerosis (mean progression rate over 3 years, 43.0 microm for current and 28.7 microm for never smokers, regardless of ETS exposure), and past smoking was associated with a 25% increase (mean progression rate over 3 years, 35.8 microm for past smokers and 28.7 microm for never smokers). Relative to those not exposed to ETS, exposure to ETS was associated with a 20% increase (35.2 microm for those exposed to ETS vs 29.3 microm for those not exposed). The impact of smoking on atherosclerosis progression was greater for subjects with diabetes and hypertension. Although more pack-years of exposure was independently associated with faster progression (P<.001), after controlling for the number of pack-years, the progression rates of current and past smokers did not differ (P=.11). CONCLUSIONS: Both active smoking and ETS exposure are associated with the progression of an index of atherosclerosis. Smoking is of particular concern for patients with diabetes and hypertension. The fact that pack-years of smoking but not current vs past smoking was associated with progression of atherosclerosis suggests that some adverse effects of smoking may be cumulative and irreversible.

Arteriosclerosis↗
PubMed1998

Work organization and atherosclerosis: findings from the ARIC study. Atherosclerosis Risk in Communities.

INTRODUCTION: The aim of this investigation was to examine the extent to which work organization (i.e., occupational stress) is associated with subclinical carotid atherosclerosis. METHODS: For that purpose we used a cross-sectional study of four U.S. community samples conducted between 1987 and 1989. Participants in the study were 10,801 adults aged 45 to 64 years. Subclinical carotid atherosclerosis was assessed by measuring the intima-media thickness (IMT) of the carotid artery wall using B-mode ultrasound. Occupational stress was defined using six indicators: substantive complexity of work, physical demands, job insecurity, skill discretion, decision authority, and physical exertion. Information from U.S. national surveys on occupational stress indicators was linked to the study participants' occupation. RESULTS: We observed negative associations of complexity of work and skill discretion with mean IMT of the carotid artery wall among the four race-gender groups. In addition, physical demands was positively associated with mean IMT among blacks and job insecurity was positively associated with IMT among white women and black men. After adjustment for well-established risk factors, the magnitude of these associations was substantially reduced. CONCLUSIONS: Taken in combination with results from recent European studies, our findings suggest that work organization plays a role in the etiology of atherosclerosis.

Adult↗