Abstract

Background: A cross-sectional design was employed to ascertain the relationship between dairy consumption and insulin resistance (IR) in 272 middle-aged, nondiabetic women. Methods: Participants kept a seven-day weighed food record to report their diets, including consumption of dairy foods. IR was assessed using the homeostatic model assessment (HOMA), using the following formula: fasting plasma insulin (µU/ml) x fasting plasma glucose (mg/dL)/405. The Bod Pod was used to examine body fat percentage, and accelerometry over a seven-day period was used to assess physical activity. HOMA values were log-transformed and regression analysis and the General Linear Model procedure were used to determine how mean HOMA differed across low, moderate, and high dairy intake groups. Results: (Mean ± SD) age: 40.1 ± 3.0 years, physical activity (average activity counts for one week, divided by 1,000): 2700.1 ± 781.9, body fat percentage: 31.7 ± 6.9, weight (kg): 66.1 ± 10.0, fasting glucose (mg/dL): 86.7 ± 5.9, fasting insulin (µU/mL): 7.0 ± 4.2, energy intake (kcal/day): 2051.9 ± 319.1, kcal from carbohydrate (%): 55.7 ± 6.2, kcal from protein (%): 13.8 ± 2.5, kcal from fat (%): 30.5 ± 5.8, soluble fiber (g per 1,000 kcal): 1.7 ± 0.9, insoluble fiber (g per 1,000 kcal): 3.8 ± 1.9, dairy intake (servings/day): 1.1 ± 1.0, HOMA: 1.5 ± 1.0, log-transformed HOMA: 0.3 ± 0.6. Those in the highest quartile for dairy consumption had significantly higher log-transformed HOMA (0.41 ± 0.53) than those in the moderate (0.22 ± 0.55) or low (0.19 ± 0.58) consumption categories (F = 6.90, p = 0.0091). This relationship remained significant after controlling for all covariates (F = 4.71, p = 0.030). Controlling for physical activity strengthened the relationship between dairy consumption and IR by 7%. Adjusting for body weight, percent of kcal from fat, and insoluble and soluble fiber intake also strengthened the relationship. Controlling for energy intake and body fat percentage weakened the relationship by 32% and 13%, respectively, though it remained significant. Conclusion: High dairy consumption is significantly associated with IR in middle-aged, nondiabetic women.

Degree

College and Department

Life Sciences; Exercise Sciences

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