Homocysteine and vitamin B(12) concentrations and mortality rates in type 2 diabetes.
OBJECTIVE
To assess the role of homocysteine as a risk factor for mortality in diabetic subjects.


METHODS
Homocysteine, vitamin B(12), and folate concentrations were measured in stored sera of 396 diabetic Pima Indians aged > or = 40 years when examined between 1982 and 1985. Vital status was assessed through 2001.


CONCLUSIONS
Over a median follow-up of 15.7 years, there were 221 deaths-76 were due to cardiovascular disease (CVD), 36 to diabetes/nephropathy and 34 to infections. Homocysteine was positively associated with mortality from all causes (hazard rate ratio (HRR) for highest versus lowest tertile of homocysteine = 1.70, 95% confidence interval (CI) 1.18-2.46), from diabetes/nephropathy (HRR = 2.39, 95% CI 0.94-6.11) and from infectious diseases (HRR = 3.39, 95% CI 1.19-9.70), but not from CVD (HRR = 1.16, 95% CI 0.62-2.17) after adjustment for age, sex and diabetes duration. Homocysteine correlated with serum creatinine (r = 0.50), and the relationships with mortality rates were not significant after adjustment for creatinine. Vitamin B(12) was positively associated with all-cause mortality (HRR for 100 pg/mL difference adjusted for age, sex and diabetes duration = 1.15, 95% CI 1.08-1.22) and death from diabetes/nephropathy (HRR = 1.27, 95% CI 1.10-1.46). The association between homocysteine and mortality in type 2 diabetes is not causal, but is confounded by renal disease in Pima Indians.
Looker
Helen C
HC
National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, AZ, USA. hlooker@mail.nih.gov
Fagot-Campagna
Anne
A
Gunter
Elaine W
EW
Pfeiffer
Christine M
CM
Sievers
Maurice L
ML
Bennett
Peter H
PH
Nelson
Robert G
RG
Hanson
Robert L
RL
Knowler
William C
WC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001130:Arizona / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000401:mortality; D002423:Cause of Death; D003404:Creatinine / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000401:mortality*; D003928:Diabetic Nephropathies / Q000401:mortality; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data; D007239:Infections / Q000401:mortality; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012709:Serum Albumin / Q000032:analysis; D014805:Vitamin B 12 / Q000097:blood*
D012709:Serum Albumin; D006710:Homocysteine; D005492:Folic Acid; D003404:Creatinine; D014805:Vitamin B 12