Effects of Heavy Alcohol Use on Fasting Glucose and Insulin Resistance in Mid-Life Adults

Abstract

Introduction: As our population ages, type 2 diabetes has become more prevalent in the United States and one in five mid-life adults (50-64 years) have type 2 diabetes. Unhealthy and heavy alcohol use (that exceeds recommended drinking limits) causes dysfunction of the liver and pancreas that can impact glucose control and thereby increase risks of type 2 diabetes. In young adults, we previously found that fasting glucose and insulin resistance were not associated with heavy alcohol use. However, it remains unclear if heavy alcohol use contributes to the development of type 2 diabetes in an aged population. Therefore, the purpose of this study is to determine the effect of heavy alcohol use on fasting glucose and insulin resistance in apparently healthy mid-life adults. Methods: Mid-life men (n=21) and postmenopausal women (n=28), non-smokers, free of obesity and major clinical diseases, were recruited from the community around the Dallas—Fort Worth metroplex. All participants underwent physical exam and fasting blood sampling. Alcohol use was assessed by the US Alcohol Use Disorders Identification Test (USAUDIT) and a dried blood spot phosphatidylethanol (PEth) test. A PEth cutoff of 20 ng/mL was used to define heavy drinkers. Insulin resistance was assessed by calculating HOMA-IR (Homeostatic model assessment for insulin resistance) as insulin (μU/L) x glucose (nmol/L)/22.5. Results: A total of 24 participants had PEth levels of <20 ng/mL (non-heavy drinkers; PEth ranged from <limit of quantification to 13 ng/mL; mean ± SEM for age: 58±1 years and body mass index: 25.2±0.6 kg/m2) and the other 25 participants had PEth levels ≥20 ng/mL (heavy drinkers; PEth ranged from 20 to 665 ng/mL; age: 57±1 years and body mass index: 25.7±0.5 kg/m2). Heavy drinkers had higher USAUDIT scores than non-heavy drinkers (11.3±1.4 vs. 3.3±0.5, p<0.001). No significant difference between these two groups were found in lipid values (P≥0.1) as well as renal (P≥0.3) and liver function values (P≥0.08). Compared to non-heavy drinkers, heavy drinkers had a higher level of fasting blood glucose (96±2 vs. 91±1 mg/dL, P=0.02), but similar blood insulin (9.2±2.5 vs. 5.5±0.5 μIU/L, P=0.2) and HOMA-IR (2.23±0.64 vs. 1.23±0.11, P=0.1). The results for stepwise linear regression model indicate that only USAUDIT score was an independent factor of fasting glucose (B=0.59, p<0.001). Conclusion: Our results indicate that compared to mid-life adult non-heavy drinkers, heavy drinkers had higher fasting blood glucose levels, despite similar renal and liver function. Our results also indicate that higher risks of alcohol use disorder were associated with higher levels of fasting glucose. These data suggest that heavy alcohol use may have negative effects on glucose regulation in aged populations and increase risks of type 2 diabetes. This work was supported by NIAAA AA028537 to CLH. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.