Radhika G, Sathya R M, Sudha V, Ganesan A, Mohan V
Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, Gopalapuram, Chennai, India.
J Assoc Physicians India. 2007 Jun;55:405-11.
The aim of the study was to determine the mean dietary salt intake in urban south India and to look at its association with hypertension.
The Chennai Urban Rural Epidemiology Study (CURES) is an ongoing population based study on a representative population of Chennai city in southern India. Phase 1 of CURES recruited 26,001 individuals aged > or = 20 years, of whom every tenth subject (n = 2600) was invited to participate in Phase 3 for detailed dietary studies and 2220 subjects participated in the present study (response rate: 84.5%). Participants with self-reported history of hypertension, diabetes or heart disease were excluded from the study (n = 318) and thus the final study numbers were 1902 subjects. Dietary salt, energy, macronutrients and micronutrients intake were measured using a validated semi-quantitative food frequency questionnaire. Diagnosis of hypertension was based on the National Cholesterol Education Programme (NCEP) Adult Treatment Panel III criteria. Logistic regression analysis was used to look at the association of dietary salt with hypertension.
Mean dietary salt intake (8.5 g/d) in the population was higher than the recommended by the World Health Organization (< 5g/d). Higher salt intake was associated with older age and higher income (p for trend < 0.0001). Subjects in the highest quintile of salt intake had significantly higher prevalence of hypertension than did those in the lowest quintile (48.4 vs 16.6%, p < 0.0001). Both systolic and diastolic blood pressure significantly increased with increase in quintiles of total dietary salt both among hypertensive and normotensive subjects (p for trend p < 0.0001). Addition of salt > 1 teaspoon/day at the dining table was associated with a higher prevalence for hypertension compared to zero added salt (38.5% vs 23.3%, Chi-square = 18.95; p < 0.0001). Multiple logistic regression analysis revealed that even after adjusting for age, gender, body mass index, total energy intake and dietary fat, total dietary salt intake was positively associated with hypertension. [Odds ratio (OR): 1.161, 95% Confidence Interval (CI): 1.115-1.209, p < 0.0001].
Intake of dietary salt in urban south India is higher than currently recommended. Increasing salt intake is associated with increased risk for hypertension even after adjusting for potential confounders. This calls for urgent steps to decrease salt consumption of the population at high risk.
本研究旨在确定印度南部城市人群的平均膳食盐摄入量，并探讨其与高血压的关联。
金奈城乡流行病学研究（CURES）是一项正在进行的基于人群的研究，针对印度南部金奈市具有代表性的人群。CURES的第一阶段招募了26,001名年龄≥20岁的个体，其中每第十名受试者（n = 2600）被邀请参加第三阶段的详细膳食研究，2220名受试者参与了本研究（应答率：84.5%）。有自我报告的高血压、糖尿病或心脏病病史的参与者被排除在研究之外（n = 318），因此最终研究对象为1902名受试者。使用经过验证的半定量食物频率问卷测量膳食盐、能量、宏量营养素和微量营养素的摄入量。高血压的诊断基于美国国家胆固醇教育计划（NCEP）成人治疗小组第三次报告的标准。采用逻辑回归分析来探讨膳食盐与高血压的关联。
该人群的平均膳食盐摄入量（8.5克/天）高于世界卫生组织推荐的摄入量（<5克/天）。较高的盐摄入量与年龄较大和收入较高相关（趋势p<0.0001）。盐摄入量最高的五分位数组中的受试者高血压患病率显著高于最低五分位数组（48.4%对16.6%，p<0.0001）。在高血压和血压正常的受试者中，收缩压和舒张压均随膳食盐总量五分位数的增加而显著升高（趋势p<0.0001）。与零添加盐相比，餐桌上添加>1茶匙/天的盐与更高的高血压患病率相关（38.5%对23.3%，卡方=18.95；p<0.0001）。多因素逻辑回归分析显示，即使在调整了年龄、性别、体重指数、总能量摄入量和膳食脂肪后，膳食盐总摄入量仍与高血压呈正相关。[比值比（OR）：1.161，95%置信区间（CI）：1.115 - 1.209，p<0.0001]。
印度南部城市人群的膳食盐摄入量高于目前推荐水平。即使在调整了潜在混杂因素后，盐摄入量增加仍与高血压风险增加相关。这就需要采取紧急措施降低高危人群的盐消费量。
