title: The association and interaction analysis of hypertension and uric acid on cardiovascular autonomic neuropathy.
abstract: BACKGROUND
  The purpose of this study was to evaluate associations among hypertension (HTN) and uric acid (UA) with cardiovascular autonomic neuropathy (CAN), and to estimate the extent to which synergistic effects of HTN and UA affect the outcome in a Chinese population.
  
  
  METHODS
  We conducted a large-scale, population-based study to analyze the association and interaction of the two factors for CAN in a sample of 2092 Chinese people. Univariate and multiple linear regression (MLR) analysis were employed to detect these relationships. Interaction on an additive scale can be calculated by using the relative excess risk due to interaction (RERI), the proportion attributable to interaction (AP), and the synergy index (S).
  
  
  RESULTS
  After adjusting for confounding factors, MLR showed that HTN was independently associated with CAN (P < 0.001). A significant interaction effect of UA and HTN on CAN was detected (P = 0.035; RETI = 1.483, 95 % CI 0.415-2.551; AP = 0.360, 95 % CI -0.043 to 0.76 and S = 1.908, 95 % CI 0.152-3.66).
  
  
  CONCLUSIONS
  Our findings suggest that HTN is independently and significantly associated with CAN and offer evidence to support the hypothesis that HTN and UA have interaction effects to influence the progression of CAN.
authors.affiliation: Department of Internal Medicine, Shanghai Anting Hospital, Jiading, Shanghai, China. xpliao135@163.com.
authors.forename: X-P
authors.initials: XP
authors.lastname: Liao
authors.affiliation: Department of Internal Medicine, Shanghai Anting Hospital, Jiading, Shanghai, China. xavierzhong@yeah.net.
authors.forename: H-W
authors.initials: HW
authors.lastname: Zhu
authors.affiliation: Department of Endocrinology and Metabolism, Shanghai Tongji Hospital, Tongji University School of Medicine, Room 517, Building 2nd, 389 Xincun Road, Shanghai, 200063, China. zengfangfang1985@163.com.
authors.forename: F
authors.initials: F
authors.lastname: Zeng
authors.affiliation: Department of Endocrinology and Metabolism, Shanghai Tongji Hospital, Tongji University School of Medicine, Room 517, Building 2nd, 389 Xincun Road, Shanghai, 200063, China. albert.tang@163.com.
authors.forename: Z-H
authors.initials: ZH
authors.lastname: Tang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D001786:Blood Glucose; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014527:Uric Acid / Q000097:blood*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D014527:Uric Acid
keywords: Cardiovascular autonomic neuropathy; Hypertension; Interaction analysis; Synergistic effect; Uric acid