Getting to know the fasting glucose levels is important in diabetes management and helps patients achieve good glycemic control. Precise estimates of the age-specific relative risks of death associated with fasting glucose may help determine better glucose targets for the management of diabetes. However, little is known about the associations of the full range of fasting glucose with all-cause mortality and the optimal range for survival according to the age when a person is diagnosed with diabetes.

This study looked at 359,645 Korean adults with diabetes who participated in health screening during 2001-2004 and followed them until 2013.Fasting serum glucose and total cholesterol were assayed. Blood pressure, smoking history, alcohol use, and known prevalent diabetes status at baseline were collected. Fasting glucose concentrations were categorized into 10 groups. Hazard ratios (HR) were calculated after adjustment for age at baseline, sex, smoking status, alcohol use, physical activity, BMI, systolic blood pressure, and total cholesterol.

Analysis revealed U-curve associations between fasting glucose and all-cause mortality. Fasting glucose levels associated with the lowest mortality were ∼90–130 mg/dL, except for in those aged 18–44 years (∼80–95 mg/dL). In 18–44 years old individuals with prevalent diabetes, overall associations and fasting glucose range for minimal mortality (80–95 mg/dL) were similar to those of individuals without known prevalent diabetes. However, in middle-aged and elderly adults with prevalent diabetes, the range for lowest mortality shifted upward to 90–130 mg/dL. The risk of death associated with hypoglycemia (<65 mg/dL), generally exceeded that of levels 170–199 mg/dL, while low-normal levels (65–84 mg/dL) showed a risk comparable with that of fasting glucose 140–169 mg/dL.

The study thus points out that optimal fasting glucose range for survival is higher in adults with than without known prevalent diabetes, except, perhaps, younger adults. A tight glucose control might, therefore, have more beneficial effects at younger ages than at older ages.

Read More