title: Impact of subclinical hypothyroidism on serum total homocysteine concentrations, the prevalence of coronary heart disease (CHD), and CHD risk factors in the New Mexico Elder Health Survey.
abstract: The serum/plasma total homocysteine (tHcy) concentration, now recognized as an independent risk factor for accelerated atherosclerotic disease, is increased in overtly hypothyroid patients, and it decreases with thyroid replacement therapy. Whether or not individuals with subclinical hypothyroidism also increase their tHcy concentrations, and whether this elevation might help to explain the increased prevalence of the atherosclerotic diseases observed in this condition, remains unclear. If individuals with subclinical hypothyroidism have higher tHcy concentrations than euthyroid subjects, there would be added incentive to treat this condition earlier. In this cross-sectional study (New Mexico Elder Health Survey) of a randomly selected sample of Medicare recipients (age > or =65 years), no significant difference in serum tHcy concentrations could be detected between the 112 participants with subclinical hypothyroidism (Groups 2 and 3) and the 643 participants with thyrotropin (TSH) values < or =4.6 microU/mL (Group 1) after adjusting for differences in gender, ethnicity, age, and serum concentrations of folate, vitamin B(12), and creatinine. Only those participants with the highest TSH levels (>10 microU/mL) (Group 3) had a significantly higher prevalence of coronary heart disease (CHD) when compared against Group 1 participants (p = 0.007). No consistent significant differences in the prevalences of CHD or in the CHD risk factors examined were observed when all participants with subclinical hypothyroidism (Groups 2 and 3 combined) were compared against Group 1 participants.
authors.affiliation: Department of Internal Medicine, School of Medicine, and Aging and Genetic Epidemiology Program, Health Science Center, University of New Mexico, Albuquerque, New Mexico 87131-5666, USA. rlindeman@salud.unm.edu
authors.forename: Robert D
authors.initials: RD
authors.lastname: Lindeman
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Romero
authors.forename: David S
authors.initials: DS
authors.lastname: Schade
authors.forename: Sharon
authors.initials: S
authors.lastname: Wayne
authors.forename: Richard N
authors.initials: RN
authors.lastname: Baumgartner
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Garry
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003327:Coronary Disease / Q000097:blood / Q000453:epidemiology*; D003404:Creatinine / Q000097:blood; D005215:Fasting / Q000097:blood; D005260:Female; D005492:Folic Acid / Q000031:analogs & derivatives / Q000097:blood; D006306:Health Surveys; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000150:complications* / Q000453:epidemiology; D008297:Male; D009516:New Mexico; D015995:Prevalence; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D003404:Creatinine; D014805:Vitamin B 12