It is well known that acute alcohol ingestion increases the risk of hypoglycaemia; most likely due to inhibitory effects of alcohol on hepatic gluconeogenesis. In addition, it is well known that chronic alcohol consumption may cause hepatic steatosis which in some individuals leads to insulin resistance and impaired glucose tolerance.
- alcohol is a recognized risk factor for hypoglycaemia in patients with type 1 diabetes (1); also this risk is prominent in insulin treated type 2 diabetics and patients on sulphonlyureas (2)
- estimated that as many as one fifth of episodes of severe hypoglycemia are attributable to alcohol, and patients frequently ask for advice about the impact of drinking on diabetes (1)
- the American Diabetes Association guidelines give limits in line with those for the general population and recommend no more than approximately 2 units absolute alcohol at a single sitting (1 unit = 8 g [10 ml or 0.35 fluid ounce]
- it has been advised that diabetic patients should not exceed an alcohol consumption of 3 units per day for men, and 2 units per day for women (3)
- for insulin-treated patients, the guidelines emphasize that dietary carbohydrate should not be omitted, that alcohol should be consumed with food or shortly before eating, and that the risk of hypoglycemia may extend for several hours after drinking
- inhibition of gluconeogenesis is cited as the main metabolic effect, but it is also pointed out that the usual symptoms of hypoglycemia may be obscured or masked by the cerebral effects of alcohol. Indeed, even moderate consumption of ethanol (6-9 units) may reduce hypoglycemia awareness and impair the counter-regulatory response to insulin-induced hypoglycaemia (1)
- the risk of lactic acidosis developing in patients taking metformin is increased with binge drinking of alcohol (3,4)
Patient advice (5):
- How Much?
- The recommendations for alcohol for people with diabetes are the same as for those without diabetes:
- The safe limits for alcohol are 2-3 units/day (maximum 14 units/week) for males and females
- Every one should try to have at least 2 consecutive alcohol-free days each week.
- Type 1 or treated with insulin/meds
- please note If your diabetes is treated by insulin or certain tablets, alcohol can cause your blood sugar level to drop too low. Make sure you carry some ID to let other people know you have diabetes, e.g. ID Card or medical tag. Alcohol can lower your blood glucose and hypoglycaemia may develop up to 16hrs after you have stopped drinking. Therefore, don't drink on an empty stomach and if drinking in the evening, have a carbohydrate snack before you go to bed. Don't miss breakfast and make sure it contains carbohydrates e.g. cereal or toast
Effects of alcohol on metabolism
Lanng et al have examined the effects of alcohol on metabolism (6) and noted:
- alcohol appears to decrease the secretion of both glucagon and insulin from the pancreas independently of the route of administration (intragastrically vs. intravenously)
- alcohol appears to be "blind" to the incretin hormones - alcohol - unlike other macronutrients (i.e. carbohydrate, lipid and protein) - does not seem to stimulate GIP or GLP-1 after intragastric administration.
Heart Disease and alcohol consumption in diabetics
- the risk of heart disease associated with alcohol consumption in diabetic patients was examined in a systematic review (7). The authors concluded that:
- moderate alcohol consumption is associated with a decreased incidence of diabetes mellitus and a decreased incidence of heart disease in persons with diabetes
- a further review (8) stated:
- routine of light or moderate alcohol consumption (<= 1 drink/day for women and 1 to 2 drinks/day for men) is associated with a lower risk for all-cause mortality, coronary artery disease (CAD), type 2 diabetes mellitus (T2D), heart failure (HF), and stroke. Conversely, heavy drinking, (>4 drinks/day) is associated with an increased risk for death and cardiovascular (CV) disease (CVD)
- heavy alcohol use is a common cause of reversible hypertension (HTN), nonischemic dilated cardiomyopathy, atrial fibrillation (AF), and stroke (both ischemic and hemorrhagic)
Hypertension and alcohol consumption in diabetics
- the association of alcohol consumption and hypertension was examined in participants of the ACCORD trial (Action to Control Cardiovascular Risk in Diabetes (9)
- cohort of T2DM patients with high CV risk, who participated in the ACCORD trial, moderate (>7 drinks per week) and heavy alcohol consumption was associated with elevated blood pressure, stage 1 and stage 2 hypertension
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