Association of insulin resistance with polymorphic variants of Clock and Bmal1 genes: A case–control study

ABSTRACT

Background: Little information is available in the literature for the correlation of insulin resistance (IR) and CLOCK gene polymorphism in Chinese population. This study aimed to investigate the relationship of HOMA-IR (homeostasis model assessment of insulin resistance) to polymorphic variants of Clock and Bmal1 genes in Chinese patients with essential hypertension.

Methods: A total of 334 outpatients with essential hypertension (103 patients of HOMA-IR positive and 231 patients of HOMA-IR negative) were recruited to analyze Clock T3111C and Bmal1 A1420G genotypes with DNA sequencing approach.

Results: Waist circumference, body mass index, glycated hemoglobin, total cholesterol, triglyceride, and plasminogen activator inhibitor-1 were significantly increased, while high-density lipoprotein cholesterol was significantly decreased in patients with HOMA-IR positive (P < .05–0.001 vs. patients with HOMA-IR negative). Twenty-four-hour ambulatory blood pressure monitoring showed that 24-h mean systolic blood pressure (SBP), especially nightime SBP, was higher in patients with HOMA-IR positive (P < .05 vs. patients with HOMA-IR negative). Notably, compared with the negative group, the distribution frequency of C allele of Clock T3111C and GG genotype of Bmal1 A1420G were significantly higher in the HOMA-IR positive group (29.1 vs. 10.8% P < .000 and 43.7 vs. 27.7% P = .007, respectively). Logistic regression analysis showed that C allele of Clock T3111C (OR = 4.128, CI 95% 2.313–7.368, p = .000) and GG genotype of Bmal1 A1420G (OR = 1.983, CI 95% 1.117–3.521, p = .019) were independent risk factors for potential HOMA-IR in Chinese patients with essential hypertension.

Conclusion: Our results indicated that Chinese hypertensive patients with C allele of Clock T3111C or GG genotype of Bmal1 A1420G might be susceptible to IR and are more likely to develop high nighttime SBP.

KEYWORDS:

• CLOCK gene polymorphism
• insulin resistance
• essential hypertension

Acknowledgments

The authors thank all the subjects participated in the study for their cooperation. We also appreciate the colleagues in the Department for their support.

Competing Interests

The authors have declared that no competing interests exist.

Additional information

Funding

This work was supported by the Provincial Natural Science Foundation of Fujian (No. 2014Y01010261) and Health Innovation Fund of Fujian (No. 2012-CXB-5). The funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript;Provincial Natural Science Foundation of Fujian [2014Y01010261].