Serum homocysteine level and protein intake are related to risk of microalbuminuria: the Hoorn Study.
BACKGROUND
Microalbuminuria (MA) is a strong predictor of cardiovascular disease, but its causes are incompletely understood. Hyperhomocysteinemia is a recently recognized risk factor for cardiovascular disease independent of established risk factors. It is not known whether hyperhomocysteinemia is associated with MA, and thus could be a possible cause of microalbuminuria.


METHODS
We studied an age-, sex- and glucose-tolerance-stratified random sample of a 50- to 75-year old general Caucasian population (N = 680). The urinary albumin-to-creatinine ratio (ACR) was measured in an early morning spot urine sample. MA was defined as an ACR > 3.0 mg/mmol.


RESULTS
The prevalence of MA was 4.3% (13 of 304) in subjects with normal glucose tolerance, 9.2% (17 of 185) in impaired glucose tolerance and 18.3% (30 of 164) in non-insulin-dependent diabetes mellitus (NIDDM); it was 3.7% (15 of 402) in subjects without hypertension and 17.9% (45 of 251) in those with hypertension. After adjusting for age, sex, glucose tolerance category, hypertension, dyslipidemia and smoking, the odds ratio [OR; 95% confidence interval (95%CI)] for MA per 5 mumol/liter total homocysteine increment was 1.33 (1.08 to 1.63). Additional adjustment for HbA1c, waist-hip ratio, protein intake and serum creatinine did not attenuate the association between MA and total homocysteine. A 0.1 g/kg.day increment of protein intake was also associated with an increased risk for MA after adjustment for age, sex, classical risk factors and serum total homocysteine [OR (95% CI); 1.20 (1.08 to 1.32)].


CONCLUSIONS
Both hyperhomocysteinemia and protein intake are related to microalbuminuria independent of NIDDM and hypertension. Hyperhomocysteinemia may partly explain the link between MA and increased risk of cardiovascular disease.
Hoogeveen
E K
EK
Institute for Research in Extramural Medicine, Vrije Universiteit, Amsterdam, The Netherlands. ellen.hoogeveen@paradigm.nl
Kostense
P J
PJ
Jager
A
A
Heine
R J
RJ
Jakobs
C
C
Bouter
L M
LM
Donker
A J
AJ
Stehouwer
C D
CD
D000368:Aged; D000419:Albuminuria / Q000097:blood* / Q000178:diet therapy / Q000453:epidemiology*; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications / Q000652:urine; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D005951:Glucose Tolerance Test; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D006977:Hypertension, Renal / Q000097:blood / Q000209:etiology / Q000652:urine; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors
D004044:Dietary Proteins; D006710:Homocysteine