Background: Hypertension (HT) and hyperhomocysteinemia (HHcy) had been considered influential factors of insulin resistance. H-type HT occurred as HHcy associated with HT. The impact of HHcy on insulin resistance in H-type HT patients remains to be estimated. The interacted effects of HHcy and HT on insulin resistance are still unclear.
Methods: A total of 790 patients were recruited and classified into four groups according to their blood pressure and plasma Hcy level, i.e., control group (C group), HHcy group (HHcy subjects without HT), HT group (HT subjects without HHcy), and H group (subjects with H-type HT). The relationship between HHcy and insulin resistance, as estimated using the HOMA-IR, was analyzed and related to blood pressure.
Results: HOMA-IR values were significantly higher in the HHcy group than the C group (2.97 (2.23-4.01) versus 2.54 (1.87-3.58), P ＜ 0.01). H-type HT patients showed more severe insulin resistance than those who only got HT (3.58 (2.59-4.85) versus 2.96 (1.90-3.49)，P ＜ 0.01). Moreover, HOMA-IR values were positively correlated with Hcy levels (r = 0.26, P ＜ 0.01). After correcting for possible risking factors, a linear regression relationship between insulin resistance and HHcy was found (β = 0.158, P ＜ 0.01). HHcy was interacted with HT on the exacerbation of insulin resistance in H-type HT patients (β = 0.501, P ＜ 0.01).
Conclusions: HHcy obviously exacerbate insulin resistance, especially in H-type HT patients. HHcy and HT have a multiplicative effect on metabolic dysfunction, which may help to interpret why these patients are suffering a high risk of cardiovascular disease and stroke.
Keywords: Cardiovascular disease; hyperhomocysteinemia; hypertension; insulin resistance; metabolic disease.