Protein Intake and Glomerular Hyperfiltration in Insulintreated Diabetics Without Manifest Nephropathy

Abstract

Protein intake in relation to glomerular filtration rate (GFR) and urinary albumin excretion (UAE) has been studied in 96 insulin-treated diabetic patients, 20-40 years of age and without nephropathy. They had diastolic blood pressures (DBP) not exceeding 90 mmHg and a GFR exceeding −2 SD of the age-related value. They were without medications except for insulin.

There were no significant differences in protein intake between diabetic patients with and without hyperfiltration (1.18 ± 0.26 g/kg/d vs 1.21 ± 0.42 g/kg/d, p = 0.75) or between diabetic patients with or without increased UAE (1.16 ± 0.41 g/kg/d vs 1.24 ± 0.37 g/kg/d, p = 0.37). No relations were found between protein intake and GFR or UAE in the whole sample, but a positive relation was found between UAE and protein intake in patients with increased UAE. Protein intake correlated with UAE in hyperfiltrators who use tobacco (n = 8. r = 0.85. p = 0.01), but not in non-users (n = 11, r = 0.24, p = 0.48).

In conclusion our findings give no support for a relation between high protein intake and glomerular hyperfiltration in insulin-treated-diabetic patients. However, in contrast to none-users of tobacco, a positive relation was found between UAE and protein intake in tobacco users with hyperfiltration.

Key words:

• diabetes
• protein intake
• hyperfiltration
• albuminuria.