Microalbuminuria in elderly hyperglycaemic patients and controls.

Detailed examination was performed in 1781 subjects with occult fasting hyperglycaemia (FH), 211 known diabetics (KD), and their corresponding non-diabetic controls (80 CFH, 216 CKD), all found by screening of a well-defined population aged 60-74 years. All but one FH and 90% of KD could be classified as non-insulin-dependent diabetes mellitus (NIDDM) when evaluated by a glucagon-C-peptide test. Urine excretion of albumin and beta 2-microglobulin and the creatinine clearance were examined over 1 hour in the resting state. The results show that elderly non-diabetics have a wide range of albumin excretion rates. Occult fasting hyperglycaemia is associated with increased albuminuria not detectable by conventional tests for urinary proteins in males, whereas females do not have increased microalbuminuria. Known NIDDM is associated with increased albuminuria in both sexes indicating a sex difference in the threshold for albuminuria only in subjects with occult fasting hyperglycaemia. The albumin/beta 2-microglobulin excretion ratio indicates that the higher albumin excretion rates associated with occult fasting hyperglycaemia and known NIDDM are of glomerular origin.