Correlation between Serum Homocysteine Level and Cystatin C Elevation in Patients with H-type Hypertension

Objective To investigate the correlation between serum levels of homocysteine (Hcy) and cystatin C (CysC), a sensitive marker of renal function, in patients with H-type hypertension. Methods A total of 857 patients with essential hypertension without moderate to severe renal impairment (estimated glomerular filtration rate ≥ 60 ml/(min-1.73 m2) by Modification of Diet in Renal Disease equation) visited the Seventh Affiliated Hospital of Sun Yat-sen University from May 2018 to May 2020 were selected as the research subjects. The observation group (n = 635) consisted of patients with H-type hypertension (essential hypertension with Hcy ≥ 10 mmol/l) and the control group (n = 222) consisted of patients with non-H-type hypertension (essential hypertension with Hcy < 10 mmol/l). Multivariate logistic regression analysis, curve fitting, and threshold analysis were used to evaluate the correlation between elevated CysC and serum Hcy levels. Results CysC in observation group was significantly higher than that in control group (0.96 ± 0.160 vs 0.84 ± 0.13 mmol/l; p < 0.001). Multivariate logistic regression analysis, curve fitting, and threshold analysis showed that there was a significant difference in the risk of CysC elevation between Hcy levels at 10-25 mmol/L and Hcy levels below 10 mmol/L; there was no significant difference in the risk of CysC elevation between Hcy levels above 25 mmol/L and Hcy levels below 10 mmol/L. The inflection point of Hcy was 15.23 mmol/L, and when Hcy was < 15.23 mmol/L, the probability of CysC elevation increased by 27% for each 1 mmol/L increase in Hcy (OR 1.27, 95% Cl: 1.12, 1.44; P = 0.0002). When Hcy was > 15.23 mmol/l, the probability of CysC elevation was reduced by 4% for each 1 mmol/l increase in Hcy (OR 0.96, 95% Cl: 0.92, 1.01; P = 0.1085). Conclusions The risk of CysC in patients with H-type hypertension is higher than that in patients with non-H-type hypertension when Hcy is between 10-25 mmol/L; and the probability of cystatin C elevation is the highest when Hcy is at 15.23 mmol/L. Keywords: Essential hypertension; H-type hypertension; Homocysteine; Early renal function; Cystatin C