Jinnie J. Rhee

Multiple Healthful Dietary Patterns and Type 2 Diabetes in the Women's Health Initiative

The relationship between various diet quality indices and risk of type 2 diabetes (T2D) remains unsettled. We compared associations of 4 diet quality indices--the Alternate Mediterranean Diet Index, Healthy Eating Index 2010, Alternate Healthy Eating Index 2010, and the Dietary Approaches to Stop Hypertension (DASH) Index--with reported T2D in the Womens Health Initiative, overall, by race/ethnicity, and with/without adjustment for overweight/obesity at enrollment (a potential mediator). This cohort (n = 101,504) included postmenopausal women without T2D who completed a baseline food frequency questionnaire from which the 4 diet quality index scores were derived. Higher scores on the indices indicated a better diet. Cox regression was used to estimate multivariate hazard ratios for T2D. Pearson coefficients for correlation among the indices ranged from 0.55 to 0.74. Follow-up took place from 1993 to 2013. During a median 15 years of follow-up, 10,815 incident cases of T2D occurred. For each diet quality index, a 1-standard-deviation higher score was associated with 10%-14% lower T2D risk (P < 0.001). Adjusting for overweight/obesity at enrollment attenuated but did not eliminate associations to 5%-10% lower risk per 1-standard-deviation higher score (P < 0.001). For all 4 dietary indices examined, higher scores were inversely associated with T2D overall and across racial/ethnic groups. Multiple forms of a healthful diet were inversely associated with T2D in these postmenopausal women.

Coffee and caffeine consumption and the risk of hypertension in postmenopausal women

BACKGROUND The associations of coffee and caffeine intakes with the risk of incident hypertension remain controversial. OBJECTIVE We sought to assess longitudinal relations of caffeinated coffee, decaffeinated coffee, and total caffeine intakes with mean blood pressure and incident hypertension in postmenopausal women in the Womens Health Initiative Observational Study. DESIGN In a large prospective study, type and amount of coffee and total caffeine intakes were assessed by using self-reported questionnaires. Hypertension status was ascertained by using measured blood pressure and self-reported drug-treated hypertension. The mean intakes of caffeinated coffee, decaffeinated coffee, and caffeine were 2-3 cups/d, 1 cup/d, and 196 mg/d, respectively. Using multivariable linear regression, we examined the associations of baseline intakes of caffeinated coffee, decaffeinated coffee, and caffeine with measured systolic and diastolic blood pressures at annual visit 3 in 29,985 postmenopausal women who were not hypertensive at baseline. We used Cox proportional hazards models to estimate HRs and their 95% CIs for time to incident hypertension. RESULTS During 112,935 person-years of follow-up, 5566 cases of incident hypertension were reported. Neither caffeinated coffee nor caffeine intake was associated with mean systolic or diastolic blood pressure, but decaffeinated coffee intake was associated with a small but clinically irrelevant decrease in mean diastolic blood pressure. Decaffeinated coffee intake was not associated with mean systolic blood pressure. Intakes of caffeinated coffee, decaffeinated coffee, and caffeine were not associated with the risk of incident hypertension (P-trend > 0.05 for all). CONCLUSION In summary, these findings suggest that caffeinated coffee, decaffeinated coffee, and caffeine are not risk factors for hypertension in postmenopausal women.

Energy adjustment of nutrient intakes is preferable to adjustment using body weight and physical activity in epidemiological analyses

OBJECTIVE Adjustment for body weight and physical activity has been suggested as an alternative to adjusting for reported energy intake in nutritional epidemiology. We examined which of these approaches would yield stronger correlations between nutrients and their biomarkers. DESIGN A cross-sectional study in which dietary fatty acids, carotenoids and retinol were adjusted for reported energy intake and, separately, for weight and physical activity using the residual method. Correlations between adjusted nutrients and their biomarkers were examined. SETTING USA. SUBJECTS Cases and controls from a nested case-control study of erythrocyte fatty acids and CHD (n 442) and of plasma carotenoids and retinol and breast cancer (n 1254). RESULTS Correlations between intakes and plasma levels of trans-fatty acids were 0·30 (energy-adjusted) and 0·16 (weight- and activity-adjusted); for erythrocyte levels, the corresponding correlations were 0·37 and 0·25. Energy-adjusted intakes of linoleic acid and α-linolenic acid were more strongly correlated with their respective biomarkers than weight- and activity-adjusted intakes, but the differences were not significant except for linoleic acid (erythrocyte). Weight- and activity-adjusted DHA intake was slightly more strongly correlated with its plasma biomarker than energy-adjusted intake (0·37 v. 0·34). Neither method made a difference for DHA (erythrocyte), carotenoids and retinol. CONCLUSIONS The effect of energy adjustment depends on the nutrient under investigation, and adjustment for energy calculated from the same questionnaire used to estimate nutrient intakes improves the correlation of some nutrients with their biomarkers appreciably. For the nutrients examined, adjustment using weight and physical activity had at most a small effect on these correlations.

Dietary Diabetes Risk Reduction Score, Race and Ethnicity, and Risk of Type 2 Diabetes in Women

OBJECTIVE To evaluate racial and ethnic differences in the association between a dietary diabetes risk reduction score and incidence of type 2 diabetes in U.S. white and minority women. RESEARCH DESIGN AND METHODS We followed 156,030 non-Hispanic white (NHW), 2,026 Asian, 2,053 Hispanic, and 2,307 black women in the Nurses’ Health Study (NHS) (1980–2008) and NHS II (1991–2009). A time-updated dietary diabetes risk reduction score (range 8–32) was created by adding points corresponding with each quartile of intake of eight dietary factors (1 = highest risk; 4 = lowest risk). A higher score indicates a healthier overall diet. RESULTS We documented 10,922 incident type 2 diabetes cases in NHW, 157 in Asian, 193 in Hispanic, and 307 in black women. Multivariable-adjusted pooled hazard ratio across two cohorts for a 10th–90th percentile range difference in dietary diabetes risk reduction score was 0.49 (95% CI 0.46, 0.52) for NHW, 0.53 (0.31, 0.92) for Asian, 0.45 (0.29, 0.70) for Hispanic, 0.68 (0.47, 0.98) for black, and 0.58 (0.46, 0.74) for overall minority women (P for interaction between minority race/ethnicity and dietary score = 0.08). The absolute risk difference (cases per 1,000 person-years) for the same contrast in dietary score was −5.3 (−7.8, −2.7) for NHW, −7.2 (−22.9, 8.4) for Asian, −11.6 (−26.7, 3.5) for Hispanic, −6.8 (−19.5, 5.9) for black, and −8.0 (−15.6, −0.5) for overall minority women (P for interaction = 0.04). CONCLUSIONS A higher dietary diabetes risk reduction score was inversely associated with risk of type 2 diabetes in all racial and ethnic groups, but the absolute risk difference was greater in minority women.

Evaluation of diet pattern and weight gain in postmenopausal women enrolled in the Women's Health Initiative Observational Study

It is unclear which of four popular contemporary diet patterns is best for weight maintenance among postmenopausal women. Four dietary patterns were characterised among postmenopausal women aged 49-81 years (mean 63·6 (sd 7·4) years) from the Womens Health Initiative Observational Study: (1) a low-fat diet; (2) a reduced-carbohydrate diet; (3) a Mediterranean-style (Med) diet; and (4) a diet consistent with the US Department of Agricultures Dietary Guidelines for Americans (DGA). Discrete-time hazards models were used to compare the risk of weight gain (≥10 %) among high adherers of each diet pattern. In adjusted models, the reduced-carbohydrate diet was inversely related to weight gain (OR 0·71; 95 % CI 0·66, 0·76), whereas the low-fat (OR 1·43; 95 % CI 1·33, 1·54) and DGA (OR 1·24; 95 % CI 1·15, 1·33) diets were associated with increased risk of weight gain. By baseline weight status, the reduced-carbohydrate diet was inversely related to weight gain among women who were normal weight (OR 0·72; 95 % CI 0·63, 0·81), overweight (OR 0·67; 95 % CI 0·59, 0·76) or obese class I (OR 0·63; 95 % CI 0·53, 0·76) at baseline. The low-fat diet was associated with increased risk of weight gain in women who were normal weight (OR 1·28; 95 % CI 1·13, 1·46), overweight (OR 1·60; 95 % CI 1·40, 1·83), obese class I (OR 1·73; 95 % CI 1·43, 2·09) or obese class II (OR 1·44; 95 % CI 1·08, 1·92) at baseline. These findings suggest that a low-fat diet may promote weight gain, whereas a reduced-carbohydrate diet may decrease risk of postmenopausal weight gain.

Associations of Glycemic Control With Cardiovascular Outcomes Among US Hemodialysis Patients With Diabetes Mellitus

Background There is a lack of data on the relationship between glycemic control and cardiovascular end points in hemodialysis patients with diabetes mellitus. Methods and Results We included adult Medicare‐insured patients with diabetes mellitus who initiated in‐center hemodialysis treatment from 2006 to 2008 and survived for >90 days. Quarterly mean time‐averaged glycated hemoglobin (HbA1c) values were categorized into <48 mmol/mol (<6.5%) (reference), 48 to <58 mmol/mol (6.5% to <7.5%), 58 to <69 mmol/mol (7.5% to <8.5%), and ≥69 mmol/mol (≥8.5%). Medicare claims were used to identify outcomes of cardiovascular mortality, nonfatal myocardial infarction (MI), fatal or nonfatal MI, stroke, and peripheral arterial disease. We used Cox models as a function of time‐varying exposure to estimate multivariable adjusted hazard ratios and 95%CI for the associations between HbA1c and time to study outcomes in a cohort of 16 387 eligible patients. Patients with HbA1c 58 to <69 mmol/mol (7.5% to <8.5%) and ≥69 mmol/mol (≥8.5%) had 16% (CI, 2%, 32%) and 18% (CI, 1%, 37%) higher rates of cardiovascular mortality (P‐trend=0.01) and 16% (CI, 1%, 33%) and 15% (CI, 1%, 32%) higher rates of nonfatal MI (P‐trend=0.05), respectively, compared with those in the reference group. Patients with HbA1c ≥69 mmol/mol (≥8.5%) had a 20% (CI, 2%, 41%) higher rate of fatal or nonfatal MI (P‐trend=0.02), compared with those in the reference group. HbA1c was not associated with stroke, peripheral arterial disease, or all‐cause mortality. Conclusions Higher HbA1c levels were significantly associated with higher rates of cardiovascular mortality and MI but not with stroke, peripheral arterial disease, or all‐cause mortality in this large cohort of hemodialysis patients with diabetes mellitus.