Inadequate Water Intake May Lead To Higher Blood Sugar Levels

A water tapThose who drink less than 0.5 litres of water a day are significantly more likely to develop hyperglycaemia (high blood sugar) according to the results of a French study published in the journal Diabetes Care last month.

The research, led by Ronan Roussel, Professor of Medicine at the Hospital Bichat in Paris, involved 3,615 adults who were followed for 9 years. Over the course of the study there were 565 new cases of hyperglycaemia which was defined as either a fasting glucose level over 6.1 mmol/L or the commencement of treatment for diabetes. After adjustment for a number of factors including age, weight, physical activity, and consumption of sugary drinks, the researchers found that compared to those who consumed less than 0.5 litres of water a day, those who drank between 0.5 and 1 litre of water a day were 32% less likely to develop hyperglycaemia while those who drank more than 1 litre of water a day were 21% less likely to develop the condition.

The researchers were encouraged by the findings however they acknowledge that further research needs to be carried out in order to confirm a link between water intake and high blood sugar.

The research was carried out because of previous observations that vasopressin, a hormone involved in homeostasis, may be linked to high blood sugar. Vasopressin levels are increased when fluid intake is low and some animal studies have found that the injection of vasopressin into the blood leads to a corresponding spike in blood sugar levels. Human studies looking at the risk of diabetes in relation to vasopressin have been rare due to the difficulty of accurately measuring circulating vasopressin levels (it is unstable and has a short half life).

One study, published in the journal Circulation in 2010, looked at the relationship between plasma copeptin, which is a surrogate for vasopressin, and diabetes risk in a group of 4742 Swedish adults. The researchers found that those with copeptin levels in the top 25% were 2.09 times more likely to develop diabetes over the course of the study than those in the bottom 25% for copeptin.