Comparing Heart Rate Reserve and High-Sensitivity C-Reactive Protein in Patients with and without Metabolic Syndrome

Absence of increase in heart rate in response to exercise indicates poor prognosis. Inflammatory factors as C-reactive protein (CRP) are associated with atherosclerosis. In this study, these two factors were compared in patients with and without metabolic syndrome.

203 individuals without and 123 individuals with metabolic syndrome were selected randomly from Isfahan Cohort Study and their demographic data, wait circumference, height and weight were recorded. Also, serum triglyceride (TG), fasting blood sugar (FBS), total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), and high-sensitivity CRP (hs-CRP) levels were measured. Heart rate reserve (HRR) was determined through exercise test carried out according to the Bruce standard protocol. The age-adjusted data was analyzed by generalized linear regression and student's t test.

The mean ages of individuals without and with metabolic syndrome were 54.16 ± 8.61 and 54.29 ± 7.60 years, respectively (P = 0.890). The mean LDL levels in subjects without and with the metabolic syndrome were 116.17 ± 24.04 and 120.12 ± 29.55 mg/dl while mean TG levels were 140.38 ± 61.65 and 259.99 ± 184.49 mg/dl and mean FBS levels were 81.81 ± 9.90 mg/dl and 107.13 ± 48.46 mg/dl, respectively; all the differences were statistically significant. The mean systolic blood pressure was 116.06 ± 13.69 mmHg in persons without metabolic syndrome and 130.73 ± 15.15 mmHg in patients with the syndrome. The values for mean diastolic levels in the two groups were 76.52 ± 6.69 and 82.84 ± 8.7 mmHg, respectively. Hs-CRP level in the metabolic syndrome group was significantly higher than the other group (P = 0.02) while HRR did not show significant difference in the two groups (P = 0.27).

In our study, no relationship was documented between HRR and the metabolic syndrome. However, elevated levels of hs-CRP were recorded in patients with metabolic syndrome.