Research Article: Associations of marital status with diabetes, hypertension, cardiovascular disease and all-cause mortality: A long term follow-up study

Date Published: April 22, 2019

Publisher: Public Library of Science

Author(s): Azra Ramezankhani, Fereidoun Azizi, Farzad Hadaegh, Tatsuo Shimosawa.


To investigate the associations of marital status with major clinical outcomes including type 2 diabetes (T2D), hypertension, cardiovascular disease (CVD) and all-cause mortality.

The study cohort (1999–2014) included 9,737 (45% male) Iranian adults with a mean age of 47.6 years. Marital status was defined as married versus never married, divorced and widowed. The relationship between marital status and the four above mentioned outcomes were investigated using Cox regression models adjusted for the main confounders, specific to each outcome.

After more than 12 years of follow-up, 1,889 (883 men) individuals developed hypertension, 1,038 (468 men) T2D, 1015 (597 men) CVD and 668 (409 men) all-cause mortality. Compared with married, being never married in men was associated with higher risk of hypertension [hazard ratio (HR): 1.55; 95% confidence interval (CI), 1.11–2.16] and all-cause mortality (2.17; 0.95–5.00; p-value = 0.066) after adjusting for confounders. Among women, compared with married status, widowed status was associated with a lower risk of T2D (0.74; 0.56–0.97) in the confounders adjusted model. Moreover, never married women had a lower risk of hypertension (0.58; 0.37–0.90) compared to married ones in the age adjusted model, a finding that did not achieve significance, after further adjustment for confounders.

We found that the relationship between marital status and health outcomes varied by gender. Being never married was an important risk factor for hypertension and tended to be a significant risk factor for mortality in men. However, among women, being widowed was associated with a lower risk of T2D.

Partial Text

Marriage, since ancient times, has always been a fundamental social institution and plays an important role in the lives of most people[1].Over the last half-century, numerous studies from different disciplines have investigated relations between marital status and various aspects of health, including cardiovascular, immune, psychiatric and behavioral-related indices [2]. However, findings on the relationship between marital status and health or mortality have been inconsistent [3]. A number of studies conducted on samples from various ethnic groups have reported that rate of all-cause and cause-specific mortality are higher among those who are unmarried, relative to their married counterparts, a relationship which is independent of various sociodemographic characteristics [4, 5]. Recently, a meta-analysis of 34 studies with more than two million participants has demonstrated the influence of marital status on the incidence of cardiovascular disease (CVD) and the prognosis after CVD [6]. The results of this meta-analysis showed that unmarried participants had increased odds of CVDs, compared with married participants. Furthermore, a number of studies have assessed relations between marital status and other chronic illness such as hypertension [7] and type 2 diabetes (T2D) [8]. A prospective study of Atherosclerosis Risk in Communities (ARIC) data [9]found that marital status was not associated with hypertension, but among women, remaining single throughout the study period was associated with an increased risk of developing T2D.A recent study showed that not being married, and more specifically, widowhood was associated with an increased risk of T2D in men [10].On the other hand, the meanings of marriage, gender roles and family structure have changed considerably over the last few decades [11]. Mean age at first marriage has increased and many people never want to get married. People divorce and remarry several times [11] and more and more women are joining the workforce [2]. Hence, despite the large number of existing scientific studies, the impact of marital status on health outcomes still remains an interesting topic among scholars, practitioners, and general communities[12].There are limited numbers of prospective studies assessing the associations of marital status and major health outcomes in the Middle East, namely in Iran with the fundamental demographic and cultural changes over the past several decades [13].

The original population (n = 9,737; 45% men) included in the analysis had a mean±SD age of 47.6±12.7 years (range 30–89 years). Baseline characteristics of men and women according to their marital status have been presented in Tables 1 and 2, respectively. There were significant differences in baseline characteristics between different groups of marital status among the male population, except for DBP, smoking, FHD and family history of CVD. Among women, there were statistically significant differences for all baseline characteristics between different marital groups, except for family history of CVD.

To the best of our knowledge, this is the first comprehensive study to evaluate the association between marital status and major health outcomes and mortality in Iran based on a longitudinal study. In this population-based study, we found that being single in men was associated with 55% increased risk of hypertension after adjusting for traditional risk factors such as age, BMI, smoking, TC and T2D.Furthermore, we found that relative to married men, those men in the never married group had a 2.17 times highe rall-cause mortality risk (marginally significant).Among women, widowed status was significantly associated with a 31% lower risk ofT2D after adjusting for the age, BMI, smoking, hypertension and FHD.

In this large Iranian cohort of adults, single status (never-married) was an important risk factor for hypertension and tended to be a significant risk factor for all-cause mortality among men. However, there was a significant lower risk of diabetes for widowed women compared to married women. Being married did not appear to affect the risk of developing CVD in both genders. In order to improve hypertension and mortality rates in Iranian population, it is necessary to make not only families but also healthcare professionals aware that unmarried men are at higher risk for hypertension and mortality.