The Effect of Low‐Dose Daily Aspirin Intake on Survival in the Finnish Centenarians Cohort

lessness and abnormal movements of the sleeping patient. Prolonged severe nocturnal hypoglycemia may result in convulsions and/or coma. Nocturnal hypoglycemia may be a cause of sudden death in insulin-treated diabetic patients.7 Gale et al. reported nocturnal hypoglycemia in 22 of 39 (56%) poorly controlled adult diabetic patients on conventional insulin therapy.8 Dornan et al. reported a prevalence of nocturnal hypoglycemia (blood glucose 2.0 mmol/l or 40 mg/dL) in 29% of 82 diabetic adults treated conventionally with twice daily insulin.9 Blood glucose concentrations at 10:00 p.m. have been shown to be predictive of nocturnal hypoglycemia. Pramming et al. reported that if blood glucose was 6.0 mmol/l (110 mg/dL) at 10:00 p.m. , then the risk of nocturnal hypoglycemia was 80%, whereas if it was 6.0 mmol/l (110 mg/dL) the likelihood of nocturnal hypoglycemia was 12%. 10 High titers of insulin antibodies may alter insulin pharmacokinetics and encourage recurrent hypoglycemia, possibly in association with altered awareness.11 Despite these numerous reports of nocturnal hypoglycemia, falls in this setting have not been described. In older patients, the avoidance of hypoglycemia is of much greater immediate importance than the long-term risk of developing microvascular complications associated with hyperglycemia. The timing of insulin injection and estimation of renal clearance are important in preventing nocturnal hypoglycemias. Delaying the evening injection to 10:00 p.m. and understanding that the decrease in creatinine clearance may prolong the duration of extended insulin may help to prevent nocturnal hypoglycemias. Regular selfmonitoring by diabetic patients of blood glucose at 10:00 p.m. , and eating a snack containing 10 g to 20 g of carbohydrate if the blood glucose is 6.0 mmol (110 mg/dL) may effectively prevent nocturnal hypoglycemia. With aging, there is a decline in the rate of insulin removal from plasma.12 There is also variability of absorption of extended-release preparations and their renal clearance in older people, which may be a significant obstacle in their use in intensified insulin regimens. This variability may be as high as 50% between individuals for the same dose and 25% between days in the same individual. In practice, it may result in hyperglycemia on one day and hypoglycemia on another day. Although the cause of variation is poorly understood, some clinical factors, such as the depth of injection (muscle or adipose tissue), may have a significant impact on the subsequent rate of insulin delivery in the circulation. Additional factors such as increased skin temperature (blankets) and nocturnal exercise, such as sexual intercourse, might also have a significant influence on the rate of insulin delivery during the night. Switching the intermediate-acting insulin to bedtime will avoid the danger of nocturnal hypoglycemia and may help to reduce fasting hyperglycemia. If the patient is currently receiving intermediate-acting insulin at bedtime, there are three options available. To reduce the risk of severe hypoglycemia, therapeutic goals of treatment should be modified to permit suboptimal glycemic control, accepting that this may have detrimental effects on the progression of vascular complications. Checking the renal function and creatinine clearance and modifying the dose of the morning intermediate-acting insulin, as done in our patient may be helpful. The final option is to place the patient on an insulin infusion pump to ensure more even insulin absorption, although this usually is not the practice consideration. This case is reported to heighten awareness that nocturnal hypoglycemia and Somogyi phenomenon should be considered in the differential diagnosis of nocturnal falls in diabetics, especially those requiring insulin. It also stresses the importance of calculating renal function in all patients on insulin and adjusting the dose and timing of insulin accordingly to prevent nocturnal hypoglycemias and the falls associated with it.