Article

Effects of a low-fat dietary intervention on glucose, insulin, and insulin resistance in the Women's Health Initiative (WHI) Dietary Modification trial

Division of Preventive Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
American Journal of Clinical Nutrition (Impact Factor: 6.92). 07/2011; 94(1):75-85. DOI: 10.3945/ajcn.110.010843
Source: PubMed

ABSTRACT Glycemic effects of the Women's Health Initiative (WHI) low-fat dietary intervention are unknown.
Our objective was to analyze the effects of the WHI low-fat dietary intervention on serum glucose and insulin and insulin resistance up to 6 y after random assignment.
Postmenopausal WHI Dietary Modification trial intervention (DM-I) and comparison (DM-C) participants with blood measures at least at baseline and year 1 (n = 2263) were included. Anthropometric measures, dietary assessments, serum glucose and insulin concentrations, homeostasis model assessment of insulin resistance (HOMA-IR) measures, and quantitative insulin sensitivity check index (QUICKI) values were obtained at baseline, year 1, year 3, and year 6. Changes in measures were compared between groups at years 1, 3, and 6 overall and within stratified analyses.
Mean (±SD) differences in changes at year 1 between the DM-I and DM-C groups were as follows: glucose, -1.7 ± 17.9 mg/dL; insulin, -0.7 ± 5.1 μIU/mL; HOMA-IR, -0.2 ± 1.9; and QUICKI, 0.004 ± 0.019 (all P < 0.05). Similar findings resulted from repeated-measures analyses comparing the intervention and comparison groups over the 6 y. Whereas normoglycemic women at baseline had a decrease in glucose at year 1 that was 1.9 ± 17.2 mg/dL greater in the DM-I than in the DM-C group, diabetic women had an increase in glucose that was 7.9 ± 20.3 mg/dL greater in the DM-I than in the DM-C group (P for interaction <0.001).
A low-fat diet was not significantly associated with adverse glycemic effects up to 6 y after random assignment in postmenopausal women. However, diabetic women experienced adverse glycemic effects of the low-fat diet. This trial is registered at clinicaltrials.gov as NCT00000611.

0 Followers
 · 
142 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nutrition plays an important role in metabolic syndrome etiology. We examined whether the Women's Health Initiative (WHI) Dietary Modification Trial influenced metabolic syndrome risk. 48,835 postmenopausal women aged 50-79years were randomized to a low-fat (20% energy from fat) diet (intervention) or usual diet (comparison) for a mean of 8.1years. Blood pressure, waist circumference and fasting blood measures of glucose, HDL-cholesterol and triglycerides were measured on a subsample (n=2816) at baseline and years 1, 3 and 6 post-randomization. Logistic regression estimated associations of the intervention with metabolic syndrome risk and use of cholesterol-lowering and hypertension medications. Multivariate linear regression tested associations between the intervention and metabolic syndrome components. At year 3, but not years 1 or 6, women in the intervention group (vs. comparison) had a non-statistically significant lower risk of metabolic syndrome (OR=0.83, 95%CI 0.59-1.18). Linear regression models simultaneously modeling the five metabolic syndrome components revealed significant associations of the intervention with metabolic syndrome at year 1 (p<0.0001), but not years 3 (p=0.19) and 6 (p=0.17). Analyses restricted to intervention-adherent participants strengthened associations at years 3 (p=0.05) and 6 (p=0.06). Cholesterol-lowering and hypertension medication use was 19% lower at year 1 for intervention vs. comparison group women (OR=0.81, 95% CI 0.60-1.09).Over the entire trial, fewer intervention vs. comparison participants used these medications (26.0% vs. 29.9%), although results were not statistically significant (p=0.89). The WHI low-fat diet may influence metabolic syndrome risk and decrease use of hypertension and cholesterol-lowering medications. Findings have potential for meaningful clinical translation.
    Metabolism: clinical and experimental 05/2012; 61(11):1572-81. DOI:10.1016/j.metabol.2012.04.007 · 3.61 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Previous research shows diminished weight loss success in insulin-resistant (IR) women assigned to a low-fat (LF) diet compared to those assigned to a low-carbohydrate (LC) diet. These secondary analyses examined the relationship between insulin-resistance status and dietary adherence to either a LF-diet or LC-diet among 81 free-living, overweight/obese women [age = 41.9 ± 5.7 years; body mass index (BMI) = 32.6 ± 3.6 kg/m(2) ]. This study found differential adherence by insulin-resistance status only to a LF-diet, not a LC-diet. IR participants were less likely to adhere and lose weight on a LF-diet compared to insulin-sensitive (IS) participants assigned to the same diet. There were no significant differences between IR and IS participants assigned to LC-diet in relative adherence or weight loss. These results suggest that insulin resistance status may affect dietary adherence to weight loss diets, resulting in higher recidivism and diminished weight loss success of IR participants advised to follow LF-diets for weight loss.
    Diabetes Obesity and Metabolism 07/2012; DOI:10.1111/j.1463-1326.2012.01668.x · 5.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: As atherosclerosis is increased in systemic lupus erythematosus (SLE) we compared dietary habits in patients with SLE with controls, and in the patients studied associations of diet components, especially fatty acids (FAs), with disease activity, serum lipids and carotid plaque presence. Methods: In all 114 patients with SLE and 122 age- and sex-matched population-based controls answered a food frequency questionnaire (FFQ). Subcutaneous abdominal fat cell aspiration was analysed as to FA content and plaque occurrence was determined by B-mode ultrasound. Results: The total diet energy intake did not differ between patients and controls. However, the patients with SLE reported a higher intake of carbohydrate, lower fibre intake and lower intake of omega-3 and omega-6, than controls (p < 0.05). In the patients, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in adipose tissue (AT) correlated negatively with disease activity (SLEDAI), r = -0.36, p = <0.001 and r = -0.33, p = < 0.001, respectively. AT omega-3 was further positively associated with serum apoA1, r = 0.29, p = 0.004, whereas AT omega-6 showed a negative association, r = -0.21, p = 0.040. These FAs also had opposite associations with plaque presence, EPA and were DHA negative, r = -0.32, p = 0.002 and r = -0.33, p = 0.001, respectively, and omega-6 positive, r = 0.22, p = 0.027. The carbohydrate intake was positively correlated to AT omega-6, r = 0.38, p < 0.001, and negatively with serum apoA1, r = -0.27, p = 0.005. Conclusion: The macronutrient dietary pattern is different in SLE as compared with controls. The low intake of omega-3 and high intake of carbohydrate among patients with SLE appear to be associated with worse disease activity, adverse serum lipids and plaque presence.
    Lupus 08/2012; 21(13):1405-11. DOI:10.1177/0961203312458471 · 2.48 Impact Factor
Show more

Preview

Download
1 Download
Available from