Diabetes Care, Vol 17, Issue 4 297-304, Copyright © 1994 by American Diabetes Association
Incipient and overt diabetic nephropathy in African Americans with NIDDM
A Dasmahapatra, A Bale, MP Raghuwanshi, A Reddi, W Byrne, S Suarez, F Nash, E Varagiannis and JH Skurnick
Division of Endocrinology and Metabolism, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark 07103.
OBJECTIVE--To determine the prevalence of incipient and overt nephropathy
in African-American subjects with non-insulin-dependent diabetes mellitus
(NIDDM) attending a hospital clinic. Contributory factors, such as blood
pressure (BP), duration and age at onset of diabetes, hyperglycemia,
hyperlipidemia, and body mass index (BMI) also were evaluated. RESEARCH
DESIGN AND METHODS--We recruited 116 African-American subjects with NIDDM
for this cross-sectional, descriptive, and analytical study. BP, BMI, 24-h
urine albumin excretion, creatinine clearance, serum creatinine, lipids,
and GHb levels were measured. Albumin excretion rate (AER) was calculated,
and subjects were divided into three groups: no nephropathy (AER < 20
micrograms/min), incipient nephropathy (AER 20-200 micrograms/min), and
overt nephropathy (AER > 200 micrograms/min). Frequency of hypertension
and nephropathy was analyzed by chi 2 testing, group means were compared
using analysis of variance, and linear correlations were performed between
AER and other variables. Multiple regression analysis was used to examine
the association of these variables while controlling for the effects of
other variables. RESULTS--Increased AER was present in 50% of our subjects;
31% had incipient and 19% had overt nephropathy. Hypertension was present
in 72.4%; nephropathy, particularly overt nephropathy, was significantly
more prevalent in the hypertensive group. Mean BP and diastolic blood
pressure (dBP) were higher in the groups with incipient and overt
nephropathy, and systolic blood pressure (sBP) was increased in overt
nephropathy. Men with either form of nephropathy had higher sBP, dBP, and
mean BP, whereas only women with overt nephropathy had increased sBP and
mean BP. Subjects with incipient or overt nephropathy had a longer duration
of diabetes, and those with overt nephropathy had a younger age at onset of
diabetes. By multiple regression analysis, AER correlated with younger age
at diabetes onset, but not with diabetes duration. No correlation with age,
lipid levels, or GHb was noted. BMI correlated with AER.
CONCLUSIONS--Incipient and overt nephropathy were observed frequently in
these African-American subjects with NIDDM. Albuminuria correlated with BP,
younger age at diabetes onset, and BMI. Association of albuminuria and
increased cardiovascular mortality may place 50% of inner-city
African-American patients with NIDDM at risk for developing cardiovascular
complications.