The interactive association between sodium intake, alcohol consumption and hypertension among elderly in northern China: a cross-sectional study

BACKGROUND: Hypertension is a worldwide public health problem. We sought to examine the interactive associations among sodium intake, alcohol consumption and hypertension among older adult residents of Inner Mongolia in northern China. METHODS: This cross-sectional study used data from the National Survey for Nutrition and Adult Chronic Disease in Inner Mongolia. The prevalence of hypertension was age standardized by the direct method. Sodium intake and alcohol consumption were estimated using a weighing method and 24-h recalls on 3 consecutive days. Hypertension was either self-reported or field-measured. Participants were categorized into six subgroups according to combinations of sodium intake status and drinking level. Logistic regression was used to determine the interactive effect of sodium intake and drinking on hypertension. RESULTS: Of the 820 older adults who participated in this study, 523 (63.80%, age-standardized rate = 62.33%) had been diagnosed with hypertension. The mean sodium intake was 4.88 g. Sodium intake and drinking excessively were both independently related to higher risk of hypertension. A formal test for a multiplicative interaction between sodium intake and drinking revealed a significant interaction (p = 0.042), and the multivariable-adjusted odds ratio (95% CI) for the interaction was 1.1 (1.0–1.3). After adjusting for confounders, compared with moderate sodium intake and no drinking group, the risk of hypertension was highest among those with both excessive sodium intake and excessive alcohol consumption, with an odds ratio of 3.6 (95% CI: 1.7–7.9). CONCLUSIONS: The study highlights the interactive effect of sodium intake and alcohol consumption on hypertension. Primary health care providers should pay special attention to older adults with hypertension—especially those with an unhealthy diet including both excessive sodium and excessive alcohol intake. These findings are applicable for older adults in Inner Mongolia and worldwide.