Alcohol Consumption and Insulin Sensitivity: AReview

Moderate alcohol consumption is associated with impaired insulin secretion and fasting glucose in non-obese non-diabetic men

AIMS/INTRODUCTION

A low insulin secretion capacity has been implicated in the high prevalence of non-obese diabetes in East Asians. As alcohol consumption alters insulin and glucose metabolism, we tested the hypothesis that alcohol consumption contributes to impaired insulin secretion and glucose intolerance in lean/normal-weight non-diabetic Japanese men.

MATERIALS AND METHODS

This cross-sectional study was undertaken among the residents of Shika town, Japan, between 2011 and 2017. A total of 402 non-diabetic men, including participants with normal fasting plasma glucose (FPG) and impaired FPG (FPG 5.6-6.9 mmol/L), and aged ≥40 years, were examined. FPG, the homeostasis model assessment of insulin secretion capacity (HOMA-B) and alcohol consumption were evaluated and compared between the body mass index (BMI) <25 and BMI ≥25 groups.

RESULTS

HOMA-B levels were lower in the BMI <25 group than in the BMI ≥25 group. Alcohol consumption correlated with a low HOMA-B level regardless of BMI, and, thus, the HOMA-B levels of alcohol drinkers were significantly lower in the BMI <25 group. A multivariable logistic regression analysis showed that alcohol consumption, even light-to-moderate consumption (1-25 g/day), was associated with significantly low levels of HOMA-B and impaired FPG in the BMI <25 group. Among participants with impaired FPG, a low level of HOMA-B was observed in alcohol drinkers, but not in non-drinkers. In contrast, light-to-moderate alcohol consumption was not related to HOMA-B or FPG in the BMI ≥25-group.

CONCLUSION

Alcohol consumption, even a small amount, might contribute to reductions in HOMA-B levels and impaired FPG in lean/normal-weight Japanese men.

Prevalence of Insulin Resistance in Adults Living with HIV: Implications of Alcohol Use

Unhealthy alcohol use is prevalent among persons living with HIV (PLWH). Aging and increased survival of PLWH on antiretroviral therapy (ART) are complicated by metabolic dysregulation and increased risk of insulin resistance (IR) and diabetes mellitus. The objective of this study was to determine the prevalence and association of IR with unhealthy alcohol use in adult in-care PLWH. A cross-sectional analysis of metabolic parameters and alcohol use characteristics was conducted in adult PLWH enrolled in the New Orleans Alcohol Use in HIV (NOAH) Study. IR was estimated using homeostatic model assessment (HOMA-IR), triglyceride index, and McAuley index and beta cell function (HOMA-β). Alcohol use was assessed using Alcohol Use Disorders Identification Test (AUDIT)-C, 30-day timeline followback (TLFB), lifetime drinking history, and phosphatidylethanol (PEth) measures. A total of 351 participants, with a mean age [±standard deviation (SD)] of 48.1 ± 10.4 years, were included (69.6% male). Of these, 57% had an AUDIT-C score of 4 or greater, indicating unhealthy alcohol use. Mean body mass index (BMI) was 27.2 ± 7.0 kg/m², 36.4% met criteria for metabolic syndrome, and 14% were diagnosed with diabetes. After adjusting for education, race, BMI, smoking status, viral load, CD4 count, use of protease inhibitors, statins, or metformin; physical activity and diabetes diagnosis, HOMA-IR, and McAuley index were negatively associated with AUDIT-C, and HOMA-β cell function was negatively associated with AUDIT-C, PEth, and TLFB. Cross-sectional analysis of NOAH participants indicates that alcohol use is associated with decreased HOMA-β cell function, suggesting dysregulation of endocrine pancreatic function.

A U-shaped relationship between alcohol consumption and cardiometabolic index in middle-aged men

BACKGROUND

Cardiometabolic index (CMI) is a new index for discriminating diabetes. The purpose of this study was to determine whether CMI is affected by habitual alcohol drinking.

METHODS

The subjects were 21572 men (35-60 years) receiving annual health checkups. They were divided by average daily ethanol consumption into non-, light (< 22 g), moderate (≥ 22 and < 44 g), heavy (≥ 44 and < 66 g) and very heavy (≥ 66 g) drinkers. Relationship between alcohol intake and CMI was investigated with adjustment for age and histories of smoking and regular exercise.

RESULTS

Log-transformed CMI was significantly lower in light, moderate and heavy drinkers than in nondrinkers and was lowest in light drinkers, while there was no significant difference in log-transformed CMI of nondrinkers and very heavy drinkers. Odds ratio vs. nondrinkers for high CMI was significantly lower than the reference level of 1.00 in light, moderate and heavy drinkers and was lowest in light drinkers but was not significantly different from the reference level in very heavy drinkers. Odds ratio of subjects with vs. those without high CMI for hyperglycemia was significantly higher than the reference level in all of the alcohol groups and was significantly lower in moderate drinkers but was not significantly different in the other drinker groups when compared with the nondrinker group.

CONCLUSION

There is a U-shaped relationship between alcohol consumption and CMI, and moderate drinking but not excessive drinking attenuates the association between CMI and hyperglycemia.

The effect of alcohol consumption on insulin sensitivity and glycemic status: a systematic review and meta-analysis of intervention studies

OBJECTIVE

Moderate alcohol consumption is associated with a reduced risk of type 2 diabetes. This reduced risk might be explained by improved insulin sensitivity or improved glycemic status, but results of intervention studies on this relation are inconsistent. The purpose of this study was to conduct a systematic review and meta-analysis of intervention studies investigating the effect of alcohol consumption on insulin sensitivity and glycemic status.

RESEARCH DESIGN AND METHODS

PubMed and Embase were searched up to August 2014. Intervention studies on the effect of alcohol consumption on biological markers of insulin sensitivity or glycemic status of at least 2 weeks' duration were included. Investigators extracted data on study characteristics, outcome measures, and methodological quality.

RESULTS

Fourteen intervention studies were included in a meta-analysis of six glycemic end points. Alcohol consumption did not influence estimated insulin sensitivity (standardized mean difference [SMD] 0.08 [-0.09 to 0.24]) or fasting glucose (SMD 0.07 [-0.11 to 0.24]) but reduced HbA1c (SMD -0.62 [-1.01 to -0.23]) and fasting insulin concentrations (SMD -0.19 [-0.35 to -0.02]) compared with the control condition. Alcohol consumption among women reduced fasting insulin (SMD -0.23 [-0.41 to -0.04]) and tended to improve insulin sensitivity (SMD 0.16 [-0.04 to 0.37]) but not among men. Results were similar after excluding studies with high alcohol dosages (>40 g/day) and were not influenced by dosage and duration of the intervention.

CONCLUSIONS

Although the studies had small sample sizes and were of short duration, the current evidence suggests that moderate alcohol consumption may decrease fasting insulin and HbA1c concentrations among nondiabetic subjects. Alcohol consumption might improve insulin sensitivity among women but did not do so overall.

Frequency of heavy alcohol drinking and risk of metabolic syndrome in middle-aged men

BACKGROUND

Frequency of alcohol drinking is known to influence cardiovascular risk. However, little is known regarding the relationship between frequency of drinking and metabolic syndrome (MetS). The aim of this study was to determine how frequency of heavy drinking modifies the prevalence of MetS.

METHODS

The subjects were middle-aged male nondrinkers and occasional or regular heavy drinkers (ethanol intake: ≥66 g per drinking day). Odds ratios (ORs) for MetS and each component comprising MetS were calculated with adjustment for age and histories of smoking and regular exercise.

RESULTS

ORs versus nondrinkers for MetS defined by the criteria of the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III) or the International Diabetes Federation (IDF) were significantly higher than the reference level of 1.00 in occasional heavy drinkers (NCEP-ATP III, 1.94 [confidence interval (CI): 1.54 to 2.45]; IDF, 1.97 [CI: 1.56 to 2.49]) and regular heavy drinkers (NCEP-ATP III, 1.48 [CI: 1.19 to 1.84]; IDF, 1.50 [CI: 1.20 to 1.86]). When compared with the reference level, OR versus nondrinkers for large waist circumference was significantly higher in occasional heavy drinkers (1.96 [CI: 1.63 to 2.35]), but not in regular heavy drinkers (1.12 [CI: 0.96 to 1.32]), while OR versus nondrinkers for hyperglycemia was significantly lower in regular heavy drinkers (0.66 [CI: 0.46 to 0.95]), but not in occasional heavy drinkers (0.86 [CI: 0.60 to 1.24]).

CONCLUSIONS

There is a positive association between heavy drinking and MetS, which is stronger in occasional drinkers than in regular drinkers. This difference may be explained by a positive association between occasional heavy drinking and central obesity and an inverse association between regular heavy drinking and hyperglycemia. The results suggest that heavy drinking, even if occasionally, is a cardiovascular risk factor.

Alcohol consumption in relation to metabolic regulation, inflammation, and adiponectin in 64-year-old Caucasian women: a population-based study with a focus on impaired glucose regulation

OBJECTIVE

The aims of this study were to examine alcohol drinking patterns in women with type 2 diabetes, impaired glucose tolerance (IGT), and normal glucose tolerance (NGT) and to investigate whether alcohol intake was associated with improved insulin sensitivity, decreased biomarkers of inflammation, and increased adiponectin levels and if these effects were limited to dysmetabolic women.

RESEARCH DESIGN AND METHODS

From a cohort of 64-year-old Caucasian women, 209 with type 2 diabetes, 205 with IGT, and 186 with NGT were recruited. Alcohol consumption and medication use were assessed by questionnaires. Anthropometric data were collected, and blood glucose, insulin, HDL cholesterol, triglycerides, C-reactive protein, white blood cell count, and serum adiponectin were measured.

RESULTS

Compared with the NGT group, alcohol consumption was lower in the IGT group and lowest in the diabetes group. Mean alcohol intakes of >9.2 and > or =3-9 g/day were positively associated with adiponectin and insulin sensitivity (homeostasis model assessment [HOMA]), respectively, independently of obesity, metabolic control, and other confounders. Alcohol intake correlated negatively with inflammatory markers, although this did not remain after adjustment for HOMA and waist circumference. The inverse associations between alcohol consumption and factors related to the metabolic syndrome such as HOMA, waist circumference, and inflammatory markers were more obvious among women with diabetes and IGT than in healthy women.

CONCLUSIONS

In these women, moderate alcohol consumption showed beneficial associations with the prevalence of type 2 diabetes, IGT, insulin sensitivity, and serum adiponectin. There is a need to clarify whether adiponectin may be a mechanistic link and also to clarify the clinical implications of these observations.