Pattern of salt intake among Iranian hypertensive patients: insights from the 2021 STEPS study

Excessive salt intake is a global health concern, particularly for individuals with hypertension (HTN). Limited research has examined the relationship between salt consumption and blood pressure control in Iranians. This study aimed to evaluate daily salt intake among hypertensive Iranians and its association with blood pressure management.

Data were obtained from Iran's 2021 STEPS survey. Sample hypertensive patients were defined by self-report, antihypertensive medication use, or blood pressure (BP) measurements (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg). Daily salt intake was estimated using the Tanaka method based on spot urine sodium levels and categorized based on calculated quartiles. BP was analyzed in both continuous and binary forms (controlled/uncontrolled). Logistic regression was applied to assess relationship between daily salt intake and uncontrolled hypertension as outcome.

The final analysis included 6,795 participants who were divided into four quartiles according to their daily salt intake. With a mean daily salt intake of 10.1 g [95% Confidence Interval (CI): 9.9-10.3], participants with undiagnosed hypertension consumed the most salt, (10.1 g [95% CI: 9.9-10.3], p = 0.002). With odds ratios (ORs) of 1.42 [95% CI: 1.16-1.74] (p = 0.001) and 1.32 [95% CI: 1.07-1.63] (p = 0.008), respectively, the third and fourth quartiles in the crude model showed noticeably higher odds of uncontrolled hypertension than the lowest quartile. Following the full adjustment model, the odds of uncontrolled hypertension were not significantly different in the fourth quartile compared to the first quartile (OR = 1.10 [95% CI: 0.87-1.39]; p = 0.404).

Since increased salt intake raises SBP and DBP, particularly in those who are unaware of their condition, this study emphasizes the urgent need for public health interventions, such as nutritional counselling for low-salt diet, to reduce salt intake, especially in the Iranian population suffering from hypertension.