Association between serum homocysteine and kidney function in hypothyroid patients: A case-control study in Northeast...

The relationship between serum homocysteine (Hcy) and kidney function in hypothyroidism is not fully understood. This case-control study investigated the association of hyperhomocysteinemia (HHcy) with kidney function tests in patients diagnosed with clinical hypothyroidism (CH).

Forty-five CH cases and 45 matched controls were recruited from a referral clinic in northeast Iran. Serum Hcy was measured using ELISA technology, and Spearman's correlation coefficients were estimated to assess the association between Hcy and various kidney function parameters.

In CH patients, the average Hcy level was significantly higher than in those with normal thyroid function (22.63 ± 1.21 vs 12.96 ± 0.24 μmol/L, p = 0.001). Among CH patients, 82.2 % had HHcy (60 % mild, 12.2 % moderate), while only 13.3 % of controls had mild HHcy. Hcy levels were positively correlated with TSH (r = 0.528; p = 0.001), eGFR (r = - 0.418; p = 0.004), urea (r = 0.371; p = 0.012), and creatinine (r = 0.384; p = 0.009) in CH patients. Multivariate logistic regression revealed a significant relationship between Hcy and CH [OR = 2.01, 95 % CI: 1.48-2.72, p = 0.001], even after adjusting for kidney parameters.

Serum Hcy was increased with progressive thyroid insufficiency, independent of changes in kidney function, and could be considered a potential risk factor for developing coronary heart disease.