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B C Chiu

Publications and source records attributed to B C Chiu.

7 recordsLinked to original sources

The relationship between agricultural environments and olfactory dysfunction.

OBJECTIVES: To examine the olfactory ability of farmers and identify exposures in agricultural environments associated with olfactory loss. STUDY DESIGN: Cross-sectional. METHODS: 405 individuals (214 males and 191 females) completed a questionnaire assessing agricultural exposures, health status, and olfactory history. Participants then completed a scratch-and-sniff 12-item odor identification test. Data analysis was conducted using the method of least squares to fit general linear models. Equality of outcome measures (the number of correctly identified odorants) between groups was evaluated using the Wilcoxon rank sum test. Differences were considered to be significant at the 0.05 level. RESULTS: Approximately 80% of participants reported active participation in farm work. Farmers correctly identified an average of 9.3 of 12 odorants, compared to 10.1 of 12 correctly identified by non-farmers, a difference that was not statistically significant (p = 0.2). Participants reporting sneezing after handling soybeans, wheat, or oats scored significantly lower than those without symptoms. There were suggestive associations between olfactory ability and exposure to anhydrous ammonia, history of wheezing and asthma, and a history of flu-like illness after farm work. CONCLUSIONS: Results indicate that, in general, farming is not associated with olfactory loss. However, we identified certain groups of farmers with inflammatory-type reactions who appeared to be susceptible to olfactory loss. The association between inflammatory reactions or conditions and olfactory loss is a novel finding.

Adolescent↗

Cigarette smoking and risk of bladder, pancreas, kidney, and colorectal cancers in Iowa.

PURPOSE: Although there are numerous reports on the effects of cigarette smoking and cancer, they have infrequently compared risks at more than one cancer site after multivariate adjustment. We analyzed data from a population-based case-control study that included five anatomic sites to evaluate the association between cigarette smoking and each cancer site and to rank the associations by site. METHODS: Study respondents included 1452 bladder, 406 kidney, 376 pancreatic, 685 colon, and 655 rectal cancer cases, as well as 2434 population controls. A self-administered questionnaire was used to collect information on cigarette smoking and other potential confounders including occupation, drinking water source, and dietary practices. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), after adjustment for age, total energy intake, and other site- and sex-specific confounders. RESULTS: In both sexes, cigarette smoking (ever vs. never) was associated with risk of bladder cancer (OR = 2.5; 95% CI, 2.0-3.1 for males; OR = 2.7; 2.0-3.6 for females) and pancreatic cancer (OR = 1.8; 1.2-2.8 for males; OR = 2.1; 1.4-3.1 for females). Cigarette smoking also increased the risk of kidney cancer among males (OR = 1.8; 1.3-2.7), and to a lesser degree, among females (OR = 1.2; 0.8-1.8). No association was found for colon or rectal cancer in either sex. CONCLUSIONS: Cigarette smoking increased the risk of bladder, kidney, and pancreatic cancer in men and women. The rankings of multivariate-adjusted ORs from highest to lowest were bladder, pancreas, kidney, and colorectum, with little difference between men and women.

Adenocarcinoma↗

Alcohol consumption and non-Hodgkin lymphoma in a cohort of older women.

We investigated the relation of alcohol consumption to risk of non-Hodgkin's lymphoma (NHL) in a cohort of 35 156 Iowa women aged 55-69 years who participated in the Iowa Women's Health Study in 1986. Alcohol consumption at baseline was obtained using a mailed questionnaire. During the 9-year follow-up period, 143 incident cases of NHL were identified. Higher alcohol consumption was significantly associated with a decreased risk of NHL (P-trend = 0.03). Compared to non-drinkers, multivariate-adjusted relative risks (RRs) were decreased for women with intake of < or = 3.4 g day(-1) (RR = 0.78; 95% confidence interval (CI) 0.51-1.21) and > 3.4 g day(-1) (RR = 0.59; 0.36-0.97). The inverse association could not be attributed to one particular type of alcoholic beverage, although red wine (RR = 0.21 for > 2 glasses per month vs non-drinker; 0.05-0.86; P-trend = 0.02) has the most distinct effect. The apparent protective effect was universal regardless of specific NHL grade or Working Formulation subtype, but was most pronounced for nodal NHL (RR = 0.48; 0.26-0.90; P-trend = 0.01) and low-grade NHL (RR = 0.52; 0.21-1.26; P-trend = 0.05). These data suggest that moderate alcohol consumption is inversely associated with the risk of NHL in older women and the amount of alcohol consumed, rather than the type of alcoholic beverages, appears to be the main effect determinant.

Aged↗

Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women.

BACKGROUND: The role of dietary protein intake in osteoporosis remains controversial. Protein is an important structural component of bone and protein supplementation improves the medical outcome of hip fracture patients, but it is unknown whether protein intake can reduce the incidence risk of hip fracture. OBJECTIVE: The relation between intake of protein and other nutrients and subsequent incidence of hip fracture was evaluated. DESIGN: Nutrient intake was assessed with a food-frequency questionnaire in a cohort of Iowa women aged 55-69 y at baseline in 1986. Incident hip fractures were ascertained through follow-up questionnaires mailed to participants in 1987 and 1989 and verified by physician reports. RESULTS: Forty-four cases of incident hip fractures were included in the analyses of 104338 person-years (the number of subjects studied times the number of years of follow-up) of follow-up data. The risk of hip fracture was not related to intake of calcium or vitamin D, but was negatively associated with total protein intake. Animal rather than vegetable sources of protein appeared to account for this association. In a multivariate model with inclusion of age, body size, parity, smoking, alcohol intake, estrogen use, and physical activity, the relative risks of hip fracture decreased across increasing quartiles of intake of animal protein as follows: 1.00 (reference), 0.59 (95% CI: 0.26, 1.34), 0.63 (0.28, 1.42), and 0.31 (0.10, 0.93); P for trend = 0.037. CONCLUSION: Intake of dietary protein, especially from animal sources, may be associated with a reduced incidence of hip fractures in postmenopausal women.

Aged↗

Family history and prostate cancer risk in a population-based cohort of Iowa men.

A family history of prostate cancer has been associated with prostate cancer risk in most prior studies, and more limited data suggest that a family history of breast cancer may also be important; however, there are no data from a population-based cohort study of prostate cancer incidence that adjusts for major confounders. We conducted follow-up through 1995 on 1557 men, ages 40-86 years, who were randomly selected (81% response rate) as cancer-free controls for a population-based case-control study conducted in Iowa from 1987-1989. Family history of cancer in parents and siblings was obtained using a mailed questionnaire. Incident cancers and deaths were ascertained through linkages to state and national databases; 101 incident cases of prostate cancer were identified. At baseline, 4.6% of the cohort reported a family history of prostate cancer in a brother or father, and this was positively associated with prostate cancer risk after adjustment for age [relative risk (RR) = 3.2; 95% confidence interval (CI), 1.8-5.7] or after multivariate adjustment for age, alcohol, and dietary factors (RR = 3.7; 95% CI, 1.9-7.2). Risk was greater if a brother had prostate cancer (RR = 4.5; 95% CI, 2.1-9.7) than if a father had prostate cancer (RR = 2.3; 95% CI, 1.0-5.3). Also at baseline, 9.6% of the cohort had a family history of breast and/or ovarian cancer in a mother or sister, and this was positively associated with prostate cancer risk (age-adjusted RR = 1.7; 95% CI, 1.0-3.0; multivariate RR = 1.7; 95% CI, 0.9-3.2). Men with a family history of both prostate and breast/ovarian cancer were also at increased risk of prostate cancer (RR = 5.8; 95% CI, 2.4-14). There was no association with a family history of colon cancer. Exclusion of well-differentiated, localized tumors did not alter these findings. These data from an incidence study confirm that a family history of prostate cancer is a strong prostate cancer risk factor after adjustment for dietary and other risk factors, and suggest that selection and recall bias have not had an important influence on most case-control study results. These data also support the idea that a family history of breast cancer may also be a prostate cancer risk factor.

Adult↗

Diet and risk of non-Hodgkin lymphoma in older women.

OBJECTIVE: To test whether high dietary intakes of fat, protein, and milk are associated with the development of non-Hodgkin lymphoma in older women. DESIGN: Prospective cohort study with a 7-year follow-up period. SETTING: General community. PARTICIPANTS: Sample of 35 156 Iowa women aged 55 to 69 years with no prior history of cancer who returned the 1986 baseline questionnaire. MAIN OUTCOME MEASURE: Non-Hodgkin lymphoma (104 incident cases). MAIN RESULTS: After controlling for age, marital status, residence, total energy intake, and transfusion history, the relative risks (RRs) for the highest tertile of intake compared with the lowest were 2.00 (95% confidence interval [CI], 1.21-3.30; P for trend = .01) for animal fat, 1.69 (95% CI, 1.07-2.67; P for trend = .02) for saturated fat, and 1.90 (95% CI, 1.18-3.04; P for trend = .01) for monounsaturated fat, and there was no association with vegetable fat or polyunsaturated fat. Greater intake of animal protein (RR = 1.52; 95% CI, 0.94-2.44; P for trend = .08), but not vegetable protein, was associated with elevated risk, and this was mainly explained by greater consumption of red meat (RR = 1.98; 95% CI, 1.13-3.47; P for trend = .02) and hamburger in particular (RR = 2.35; 95% CI, 1.23-4.48; P for trend = .02). Milk and dairy product consumption were not associated with elevated risk. There was also a decreased risk of non-Hodgkin lymphoma with greater consumption of fruits (RR = 0.64; 95% CI, 0.40-1.05; P for trend = .07). CONCLUSIONS: A high-meat diet and a high intake of fat from animal sources is associated with an increased risk of non-Hodgkin lymphoma in older women.

Aged↗