Is Increased Water Consumption Among Older Adults Associated with Improvements in Glycemia?
The high rates of obesity and impaired glycemia in older adults place these individuals at risk for developing diabetes. Dehydration, glucose tolerance, and insulin resistance are related. Many older adults do not achieve the Dietary Reference Intake (DRI) for water, and aging and dehydration are both associated with decreased glucose tolerance. Conversely, weight loss is associated with improvements in glucose tolerance. For older adults following a hypocaloric diet, additional water consumption may lead to greater weight loss. Furthermore, research suggests an association between insulin resistance and arginine vasopressin (AVP), the hormone responsible for regulating body water retention. Analysis of the association between plasma copeptin (an AVP derivative) and fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) may provide further insight into the relationship between dehydration and diabetes risk.
To our knowledge, few investigations have addressed this relationship between dehydration, impaired glycemia, and insulin resistance and how increasing water consumption may influence diabetes risk. Our purpose was to investigate the possibility that increased water consumption among older adults (n=29, BMI=31+1 kg/m2, age=62+1 years) could improve glycemia beyond that observed with weight loss, as well as associations between plasma copeptin and diabetes risk. Analysis of diabetes-related variables for subjects grouped according to study intervention group, amount of drinking water consumed, or pair-matched for weight loss and gender did not reveal significant differences between groups. Improvements in fasting insulin for water group participants, as well as correlations between hydration and insulin resistance support the need for future investigations.