Plasma Homocysteine Levels in Hyperthyroid Patients

Abstract

Abstract. Hyperhomocysteinemia is a risk factor for premature atherosclerotic vascular diseases. It is known that plasma homocysteine levels are higher in hypothyroid patients compared to healthy subjects. The aim of our study was to assess plasma total homocysteine concentrations in hyperthyroid patients before and after treatment when euthyroid status was reached and compare them with control group. Thirteen hyperthyroid patients (age, 42.9 ± 15.6 year) and eleven healthy subjects (age, 39.9 ± 12.5 year) were involved in the study. Plasma levels of homocysteine and serum cholesterol, triglyceride, HDL cholesterol, urea, creatinine, vitamin B12, folate were measured before and after treatment. LDL cholesterol and creatinine clearences were calculated. Pretreatment homocycteine levels of the hyperthyroid patients were significantly lower than healthy controls (11.5 ± 3.6 mmol/L vs. 15.1 ± 4.5 mmol/L, respectively, p<0.05). Posttreatment homocysteine levels were significantly higher than pretreatment levels (13.9 ± 6.3 mmol/L vs. 11.5 ± 3.6 mmol/L, respectively, p<0.05) and posttreatment creatinine clearance were lower than pretreatment level (103.5 ± 12.7 ml/min vs. 114.2 ± 9.3 ml/min, respectively, p<0.01). Lower homocysteine levels in hyperthyroidism can be partially explained with the changes in creatinine clearance.

Serum Cobalamin and Methylmalonic Acid Concentrations in Hyperthyroid Cats Before and After Radioiodine Treatment

“…Similar to hyperthyroidism in women, the results of this study suggest feline hyperthyroidism is not associated with a clinically important functional deficiency in cobalamin . However, the prevalence of hyperthyroid/hypocobalaminemia in this study is in contrast with the a recent retrospective study which reported a 40% prevalence in their population of hyperthyroid cats .…”

“…In a recent study, a significant decrease in serum cobalamin concentrations were reported in hyperthyroid cats, however, MMA concentrations were not measured and the change in cobalamin status after treatment for hyperthyroidism was not assessed . Low serum cobalamin concentrations are also associated with hyperthyroidism in humans but are considered functionally unimportant as serum cobalamin levels rise significantly once euthyroid . Based on known differences in nutritional requirements as well as a much higher cobalamin turnover in cats, feline hyperthyroidism may be a risk factor for a functional cobalamin deficiency and a clinical population of cats that may benefit from cobalamin supplementation …”

“…Low serum cobalamin concentrations are also associated with hyperthyroidism in humans but are considered functionally unimportant13, 14 as serum cobalamin levels rise significantly once euthyroid 15, 16. Based on known differences in nutritional requirements as well as a much higher cobalamin turnover in cats,8 feline hyperthyroidism may be a risk factor for a functional cobalamin deficiency and a clinical population of cats that may benefit from cobalamin supplementation 5…”

Homocysteine Levels and Oxidative Stress Parameters in Patients With Adult ADHD

“…The authors have attributed this phenotype to low folate and low creatinine clearance in patients with hypothyroidism, and increased creatinine clearance in patients with hyperthyroidism (Diekman, van der Put, Blom, Tijssen, & Wiersinga, 2001). Demirbas et al have proposed that an increase in creatinine clearance could be the reason for the decrease in plasma homocysteine levels of patients with hyperthyroidism brought to euthyroid status (Demirbas et al, 2004). In our study, the low plasma homocysteine in A-ADHD patients could be due to increased metabolism by hormones, as seen in hyperthyroidism, and therefore increasing glomerular filtration rate thus speeding up homocysteine elimination.…”

Folat Eksikliği ve Probiyotikler

“…Folat metabolizmasında yer alan MTHFR, MS ve CBS (sistatyon beta sentaz) aktivitelerinin tiroid hormonundan etkilendiği bildirilmektedir. Hipertirodizmde folat düzeyinin yüksek, hipotirodizmde ise düşük olduğu vurgulanmaktadır [37].…”