OBJECTIVETo investigate the combined effects of alcohol consumption and obesity hypertension risk.

METHODSBased on data from program "Prevention of multiple metabolic disorders and metabolic syndrome in Jiangsu province", Baseline data were obtained in April 1999 to Jun 2004, we conducted the follow up investigation from March 2006 to October 2007 for subjects, those follow up time meet 5 years. A total of 4 083 participants completed the follow-up survey, and 2 778 eligible participants for final analysis. In the baseline and follow up survey, participants returned a completed questionnaire with information on diet, education, occupation, lifestyle factors, and medical history. Data on demographic characteristics, physical examination and laboratory tests were also obtained. Cox proportional hazards regression model was used to investigate the association between body mass index (BMI), waist circumference (WC) and waist to height ratio (WHtR). Logistic regression model was used to examine the interaction of alcohol consumption with WC, BMI and WHtR on risk of hypertension and the relative excess risk due to interaction (RERI), the attributable proportion due to interaction (AP), and the synergy index (SI) were calculated. If the 95% CI of SI do not include 1, the 95% CI of RERI and AP do not include 0, the interactions are statistically significant.

RESULTSIn the study subjects, 660 patients (254 males and 406 females) were new cases, who developed hypertension by the follow-up investigation. The mean of WC, BMI and WHtR were (23.3 ± 3.2) kg/m(2), (77.7 ± 9.0) cm and 0.49 ± 0.06, were higher than that in normal subjects ((22.4 ± 3.0) kg/m², (74.8 ± 8.5) cm and 0.47 ± 0.05, all P values < 0.001). After adjustment for age, sex, smoking status, family history of hypertension, the hazard ratio of EH for participants with obesity, high WC, high WHtR and alcohol consumption were higher, the HR (95% CI) were 2.12 (1.46-3.10), 1.64 (1.32-2.03), 2.80 (1.73-4.59) and 1.65 (1.29-2.12). HR (95% CI) of subjects with both abnormal BMI and current alcohol consumption was 2.76 (2.45-3.17), SI (95% CI) was 1.60 (0.48-5.28), RERI(95%CI) was 0.66 (-0.47-1.79) and AP was 0.24 (-0.22-0.69), HR (95% CI) of subjects with both high WC and current alcohol consumption was 4.93 (2.87-8.49), SI(95% CI) was 4.49(1.97-10.22), RERI (95%CI) was 3.06 (0.48-5.64) and AP(95% CI) was 0.62 (0.41-0.83), HR (95% CI) of subjects with both high WHtR and current alcohol consumption was 2.80 (1.73-4.59), SI (95% CI) was 2.14 (0.88-5.17), RERI was 0.96 (0.48-5.64) and AP (95% CI) was 0.34 (0.03-0.68).

CONCLUSIONBoth obesity, high WC, high WHtR, and alcohol consumption were strong risk factors of EH, and impact of an additive interaction of alcohol consumption and high WC on EH risk existed.