Dataset Information

The effect of high compared with low dairy consumption on glucose metabolism, insulin sensitivity, and metabolic flexibility in overweight adults: a randomized crossover trial.

ABSTRACT:

Background

Dairy products contain many nutritious components that may benefit metabolic health. There are indications that glucose metabolism and insulin sensitivity, which are generally disturbed in overweight and obese individuals, may improve by increased dairy intake. This may also affect one's metabolic flexibility.

Objective

The aim of this study was to investigate the effects of high compared with low dairy intake on glucose metabolism, insulin sensitivity, and metabolic flexibility in overweight adults (aged 45-65 y).

Methods

In this randomized intervention study, subjects consumed a high- and a low-dairy diet [HDD (5-6 dairy portions) and LDD (≤1 dairy portion), respectively] for 6 wk in a crossover design, with a washout period of 4 wk. Dairy portions were 200 g semi-skimmed yoghurt, 30 g reduced-fat (30+) cheese, and 250 mL semiskimmed milk and buttermilk. After 6 wk, a 75-g oral-glucose-tolerance test (13C-labeled) and a subsequent fasting challenge were performed. Metabolic flexibility was studied by determining the respiratory quotient (RQ) using indirect calorimetry. Fasting and postprandial plasma concentrations of glucose and insulin were analyzed. The dual isotope technique enabled calculation of glucose kinetics.

Results

The study was completed by 45 overweight men and postmenopausal women [age 58.9 ± 4.3 y, BMI 27.9 ± 1.9 kg/m2 (mean ± SD)]. Fasting RQ and ΔRQ, reflecting metabolic flexibility, did not differ after both diets. Fasting glucose concentrations were similar, whereas fasting insulin concentrations were lower after the LDD (LDD: 8.1 ± 2.8 mU/L; HDD: 8.9 ± 3.3 mU/L; P = 0.024). This resulted in a higher HOMA-IR after the HDD (P = 0.027). Postprandial glucose and insulin responses as well as glucose kinetics were similar after both diets.

Conclusions

The amount of dairy intake during a 6-wk period had a neutral effect on metabolic flexibility or postprandial glucose metabolism in middle-aged overweight subjects. More trials are needed to study the effects of specific dairy types and to differentiate between metabolic subgroups. This trial was registered at trialregister.nl as NTR4899.

SUBMITTER: Eelderink C

PROVIDER: S-EPMC6537937 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Aims/hypothesisTo determine whether 6 weeks of daily, moderate alcohol consumption increases expression of the gene encoding adiponectin (ADIPOQ) and plasma levels of the protein, and improves insulin sensitivity in postmenopausal women.MethodsIn a randomised, open-label, crossover trial conducted in the Netherlands, 36 apparently healthy postmenopausal women who were habitual alcohol consumers, received 250 ml white wine ( approximately 25 g alcohol/day) or 250 ml of white grape juice (control) daily during dinner for 6 weeks. Randomisation to treatment allocation occurred according to BMI. Insulin sensitivity and ADIPOQ mRNA and plasma adiponectin levels were measured at the end of both periods. Insulin sensitivity was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Levels of ADIPOQ mRNA in subcutaneous adipose tissue were determined by RT-PCR.ResultsAll subjects completed the study. Six weeks of white wine consumption reduced fasting insulin (mean +/- SEM 40.0 +/- 3.4 vs 46.5 +/- 3.4 pmol/l; p < 0.01) and HOMA-IR (1.42 +/- 0.13 vs 1.64 +/- 0.13; p = 0.02) compared with 6 weeks of grape juice consumption. ADIPOQ mRNA levels (1.09 +/- 0.15 vs 0.98 +/- 0.15; p = 0.04) and plasma levels of total (13.1 +/- 0.8 vs 12.0 +/- 0.8 microg/ml; p < 0.001) and high molecular weight (HMW) adiponectin (9.9 +/- 1.2 vs 8.8 +/- 1.2 microg/ml; p = 0.02) significantly increased after alcohol compared with juice consumption. Changes in ADIPOQ mRNA levels correlated with changes in plasma levels of total adiponectin (rho = 0.46; p < 0.01). Both fasting triacylglycerol (8.2%; p = 0.04) and LDL-cholesterol levels (7.8%; p < 0.0001) decreased, whereas HDL-cholesterol increased (7.0%; p < 0.0001) after prolonged moderate alcohol intake. No notable adverse effects were reported.Conclusions/interpretationModerate alcohol consumption for 6 weeks improves insulin sensitivity, adiponectin levels and lipid profile in postmenopausal women. Furthermore, these data suggest a transcriptional mechanism leading to the alcohol-induced increase in adiponectin plasma levels.