Cystatin C and cardiac hypertrophy in primary hypertension.

BACKGROUND

Cystatin C is a marker of kidney function and a predictor of cardiovascular morbidity and mortality. It is unknown whether this protein may be related to the cardiac involvement that is common among patients with essential hypertension.

METHODS

We evaluated the relationship between serum cystatin C, serum creatinine, estimated glomerular filtration rate and cardiac structure assessed by echocardiography, in a group of 49 non-diabetic patients with primary hypertension and normal serum creatinine.

RESULTS

Mean cystatin C levels were 0.74 +/- 0.15 mg/l. Age, body mass index, triglycerides and creatinine, estimated glomerular filtration rate and left ventricular mass index were independently associated with cystatin C levels. Seventy three per cent of patients had cardiac hypertrophy. The prevalence of left ventricular hypertrophy was higher in patients who had cystatin C levels above the 70th percentile (0.79 mg/dl) than patients below this percentile (93.3% vs 66.7%, respectively, p = 0.04). Serum cystatin C (beta = 0.48, p = 0.009), but not serum creatinine nor estimated glomerular filtration rate, was independently related to left ventricular mass index in a logistic regression analysis.

CONCLUSIONS

Cystatin C is closely related to left ventricular mass in hypertensive patients, and could be a marker for cardiac hypertrophy in these patients.