Jaakko Mursu

Dietary Supplements and Mortality Rate in Older Women: The Iowa Women's Health Study

BACKGROUND Although dietary supplements are commonly taken to prevent chronic disease, the long-term health consequences of many compounds are unknown. METHODS We assessed the use of vitamin and mineral supplements in relation to total mortality in 38,772 older women in the Iowa Womens Health Study; mean age was 61.6 years at baseline in 1986. Supplement use was self-reported in 1986, 1997, and 2004. Through December 31, 2008, a total of 15,594 deaths (40.2%) were identified through the State Health Registry of Iowa and the National Death Index. RESULTS In multivariable adjusted proportional hazards regression models, the use of multivitamins (hazard ratio, 1.06; 95% CI, 1.02-1.10; absolute risk increase, 2.4%), vitamin B(6) (1.10; 1.01-1.21; 4.1%), folic acid (1.15; 1.00-1.32; 5.9%), iron (1.10; 1.03-1.17; 3.9%), magnesium (1.08; 1.01-1.15; 3.6%), zinc (1.08; 1.01-1.15; 3.0%), and copper (1.45; 1.20-1.75; 18.0%) were associated with increased risk of total mortality when compared with corresponding nonuse. Use of calcium was inversely related (hazard ratio, 0.91; 95% confidence interval, 0.88-0.94; absolute risk reduction, 3.8%). Findings for iron and calcium were replicated in separate, shorter-term analyses (10-year, 6-year, and 4-year follow-up), each with approximately 15% of the original participants having died, starting in 1986, 1997, and 2004. CONCLUSIONS In older women, several commonly used dietary vitamin and mineral supplements may be associated with increased total mortality risk; this association is strongest with supplemental iron. In contrast to the findings of many studies, calcium is associated with decreased risk.

Dietary Supplements and Mortality Rate in Older Women

BACKGROUND Although dietary supplements are commonly taken to prevent chronic disease, the long-term health consequences of many compounds are unknown. METHODS We assessed the use of vitamin and mineral supplements in relation to total mortality in 38,772 older women in the Iowa Womens Health Study; mean age was 61.6 years at baseline in 1986. Supplement use was self-reported in 1986, 1997, and 2004. Through December 31, 2008, a total of 15,594 deaths (40.2%) were identified through the State Health Registry of Iowa and the National Death Index. RESULTS In multivariable adjusted proportional hazards regression models, the use of multivitamins (hazard ratio, 1.06; 95% CI, 1.02-1.10; absolute risk increase, 2.4%), vitamin B(6) (1.10; 1.01-1.21; 4.1%), folic acid (1.15; 1.00-1.32; 5.9%), iron (1.10; 1.03-1.17; 3.9%), magnesium (1.08; 1.01-1.15; 3.6%), zinc (1.08; 1.01-1.15; 3.0%), and copper (1.45; 1.20-1.75; 18.0%) were associated with increased risk of total mortality when compared with corresponding nonuse. Use of calcium was inversely related (hazard ratio, 0.91; 95% confidence interval, 0.88-0.94; absolute risk reduction, 3.8%). Findings for iron and calcium were replicated in separate, shorter-term analyses (10-year, 6-year, and 4-year follow-up), each with approximately 15% of the original participants having died, starting in 1986, 1997, and 2004. CONCLUSIONS In older women, several commonly used dietary vitamin and mineral supplements may be associated with increased total mortality risk; this association is strongest with supplemental iron. In contrast to the findings of many studies, calcium is associated with decreased risk.

Diet quality indexes and mortality in postmenopausal women: the Iowa Women's Health Study

BACKGROUND A priori diet scores such as the Alternative Healthy Eating Index (AHEI) and the food-based a priori diet quality score predict chronic disease risk. OBJECTIVE We compared the AHEI and a priori diet quality score relative to mortality. DESIGN Postmenopausal women who were free of diabetes, cardiovascular disease (CVD), and cancer in the Iowa Womens Health Study (in 1986, n = 29,634 with a mean 6 SD age of 61.4 6 4.2 y; in 2004, n = 15,076 with a mean 6 SD age of 79.7 6 4.0 y). A food-frequency questionnaire was used. Through 31 December 2008, 10,343 total, 3646 CVD, 3207 cancer, and 2888 inflammatory-related deaths were identified through record linkage. HRs were computed for quartiles of each diet score at baseline and 2004. To compare scores, the residual of each score given the other score was computed by using linear regression. RESULTS At baseline, indexes had a correlation of 0.65. For the AHEI, the multivariable-adjusted HRs (95% CIs) for total, CVD, cancer, and inflammatory-related mortality were 0.82 (0.77, 0.87), 0.79 (0.72, 0.88), 0.88 (0.79, 0.98), and 0.76 (0.68, 0.84), respectively. The a priori score had corresponding HRs of 0.80 (0.76, 0.85), 0.79 (0.72, 0.88), 0.86 (0.77, 0.95), and 0.75 (0.67, 0.84), respectively. Each score added information to the other score for total, CVD mortality, and inflammatory-related mortality. In 2004, both scores predicted total, CVD, and inflammatory-related mortality, and the a priori score also predicted cancer mortality. The a priori score added independent information for all outcomes except cancer, whereas the AHEI added information only for total mortality. CONCLUSION Two correlated diet quality scores predicted total and disease-specific mortality, but their residuals also predicted complementarily.

Whole grain intake, incident hip fracture and presumed frailty in the Iowa Women's Health Study

Whole cereal grain foods are rich in phytate, a Ca chelator, and could increase the risk of hip fracture. The objective of the present study was to investigate the association between baseline whole grain intake and incident hip fracture. In the present study, 29 192 women who at baseline in 1986 were aged 55-69 years, free of diabetes, and reported a plausible energy intake of 2508-20 900 kJ/d and reported no fracture since the age of 35 years were followed. Hip fracture (n 746) was self-reported in five questionnaires through 2004. Of 1451 hip fractures identified passively by Medicare linkage through 31 December 2004 (Medicare hip fracture), 507 had also been self-reported. Whole grain intake was inversely related to Medicare hip fracture (P trend = 0.02), but it was unrelated to self-reported hip fracture (P trend = 0.27). The hazard ratio in the highest to lowest quintile of whole grain intake for incident Medicare-only hip fracture (n 944) was 0.66 (95% CI 0.53, 0.82) after adjustment for age, energy intake, education, BMI, waist-to-hip ratio, farm residence, physical activity, oestrogen use, smoking, alcohol use, history of cancer and other dietary variables. Medicare-only cases may have failed to self-report due to severe illness; hazard ratio for total mortality after hip fracture was 2.92 (2.37, 3.59) for Medicare-only cases v. Medicare-confirmed self-reported cases. In conclusion, in this cohort, the inverse association between whole grain intake and hip fracture was explained by ascertainment bias. Whole grain intake may increase the ability to respond to a questionnaire and self-report hip fracture, and could reflect less undocumented frailty.