Effectiveness of polypill for primary and secondary prevention of cardiovascular disease: a pragmatic cluster-randomised controlled trial (PolyPars)

Causes and predictors of premature death in the pars cohort study, Iran: a cohort study

BACKGROUND

While death in old age is inevitable, premature death at younger ages is within our control. Premature mortality (death < 70 years) is a crucial indicator of health status and access to healthcare, with variations observed across regions. In North Africa and the Middle East, ischemic heart disease (IHD), road injuries, stroke, and chronic kidney disease are projected to be the main causes of premature mortality. Unfortunately, few studies have been conducted on premature mortality worldwide. This study aimed to analyze the causes of premature death and associated risk factors within the Pars Cohort Study.

METHODS

The Pars Cohort Study is a prospective cohort study conducted in Fars Province, Iran, involving 9,264 individuals aged 40-75 years, 53.8% of whom were women. We assessed participants from baseline (2012-2014) to 2021. The data were gathered through interviews, biological samples, and physical examinations. The causes of premature mortality, hazard ratios (HRs), and population attributable fraction (PAF) with 95% confidence intervals (95% CIs) for the variables were calculated.

RESULTS

Out of 388 deaths, 54% were premature. The most common causes of premature death included IHD (40%), stroke (11%), road traffic injuries (6%), lower respiratory infections (5%), and COVID-19 (3%). The predictive factors [adjusted HRs (95% CIs)] associated with premature mortality included age [year, 1.07 (1.04, 1.10)], tobacco [1.43 (0.96, 2.11)], opium [2.12 (1.39, 3.24)], hypertension [1.52 (1.10, 2.12)], waist circumference [cm, 1.03 (1.00, 1.05)], female sex [0.30 (0.19, 0.47)], education [> 8 years vs. no formal schooling, 0.46 (0.24, 0.88)], being married [0.60 (0.37, 0.97)], physical activity [3rd vs. 1st tertile, 0.38 (0.26, 0.57)], hip circumference [cm, 0.96 (0.92, 0.99)], estimated GFR [mL/min/1.73 m², 0.99 (0.978, 0.999)], and wealth score [4th vs. 1st quartile, 0.54 (0.32, 0.90)]. The PAF (95% CI) for all modifiable predictors was 0.83 (0.62, 0.92).

CONCLUSIONS

The predominant causes of premature mortality were IHD and stroke. To mitigate premature deaths, it is recommended to address both socioeconomic and behavioral factors simultaneously.

Prevalence and Incidence of Metabolic Syndrome and Its Components Among Waterpipe Users

Objectives

To determine the associations between waterpipe use, duration, and intensity of use with prevalence and incidence of metabolic syndrome and its components (increased waist circumference, triglycerides, fasting glucose, blood pressure and decreased high-density lipoprotein cholesterol).

Methods

We conducted cross-sectional and prospective analyses using data from the Pars Cohort Study in southern Iran, encompassing 9,264 participants at the baseline, and 5,002 randomly selected in a repeated follow-up. We used multivariate logistic regression models adjusted for age, sex, education, wealth score, physical activity and cigarette pack-years to report odds ratios (OR) and 95% confidence intervals (CI).

Results

Among 9,264 participants, 3,119 (33.7%) had metabolic syndrome, and 3,482 (37.6%) had ever smoked waterpipe, with both more common in women than in men. In adjusted models, former waterpipe use was significantly associated with prevalence (OR = 1.43, 95% CI: 1.23-1.68) and incidence (OR = 1.57, 95% CI: 1.19-2.06) of the metabolic syndrome while current waterpipe use was not. Past use was associated with increased risk in all components of metabolic syndrome; current use was associated with increases in all except high blood glucose and hypertension. Past waterpipe users had higher waterpipe use intensity (before quitting) in comparison with current users (2.3 vs. 2.0 waterpipes per day, p < 0.01) and had started waterpipe smoking at a younger age (27.2 vs. 30.1 years, p < 0.01).

Conclusion

Waterpipe use was associated with metabolic syndrome and its components, especially among former users potentially due to higher intensity and earlier initiation of use.