Glomerular hyperfiltration in type I, type II, and secondary diabetes.

Glomerular hyperfiltration, a risk factor for diabetic nephropathy, has been reported in type I insulin-dependent diabetics, but it is not clear if it occurs in other types of diabetes. To ascertain the prevalence of glomerular hyperfiltration in various types of diabetes, we measured glomerular filtration rate (GFR) in 158 diabetics (91 type I, 36 type II without insulin treatment, 20 type II with insulin treatment, and 11 subjects with diabetes secondary to chronic pancreatitis), and classified them as hyper-, normo-, or hypofiltration according to values measured in 36 age-match controls. After elimination of subjects with overt renal disease or hypertension, glomerular hyperfiltration was detected in 35% of the type I diabetics, 32% of the type II diabetics without insulin treatment, one subject with chronic pancreatitis, and one type II diabetics with insulin treatment. Glomerular hyperfiltration was associated with high blood glucose in type I, insulin-dependent diabetics, and with a high apolipoprotein B/A1 ratio in type II, non-insulin-dependent diabetics without insulin treatment. In all subjects with glomerular hyperfiltration, GFR values and urinary albumin excretion were positively related (r = 0.33; n = 34; p = 0.05). Glomerular hyperfiltration is detectable among all types of diabetics.