Longitudinal study of fasting serum glucose concentrations in healthy elderly. The New Mexico Aging Process Study

The American Diabetes Association s Expert Committee on the Diagnosis and Classification of Diabetes Mellitus has made the recommendation that all individuals over the age of 45 years should be screened for diabetes every 3 years.

This study was designed to determine the necessity for screening healthy elderly (> 65 years) this frequently using fasting serum glucose (FSG) determinations.

This is a longitudinal study of initially healthy, upper middle class, community-based volunteers, mostly age 65 years and older at entry into the study. Participants were followed longitudinally with annual FSG concentrations and body mass indices (BMI) for periods up to 18 years (mean 12.4 years).

Only 4 of 299 individuals with entry FSG < 126 mg/dl (mean + S.D. age at entry 71.6 + 4.8 years) and 6 or more annual visits have subsequently met the Expert Committee criteria for the diagnosis of diabetes (two consecutive FSGs > 126 mg/dl unless under treatment). When one examines the slopes of FSGs plotted over time (years) for each individual, more participants had a negative slope (220) than positive slope (79), i.e., their FSGs tended to decrease with age. None of the 68 individuals entered age > 75 years subsequently developed diabetes or a significantly positive slope.

It does not appear necessary to screen non-obese elders (excluding minorities) age >65 years with a FSG < 100 mg/dl, or those age >75 years every 3 years as recommended.