The impact of COVID-19 on mortality among diabetic and hypertensive individuals in coastal communities in Bangladesh: evidence from chakaria health and demographic surveillance system

Background COVID-19 was initially considered to be primarily a respiratory illness. However, it soon became evident that individuals with non-communicable diseases (NCDs), particularly Diabetes Mellitus (DM) and Hypertension (HTN), faced a markedly higher risk of severe illness and death. This study assessed excess mortality during the COVID-19 pandemic among individuals living with DM and HTN in rural coastal communities in Bangladesh. Methods The study utilised data from the Chakaria Health and Demographic Surveillance System (HDSS), located in the rural sub-district of Chakaria in southeast Bangladesh on the coast of the Bay of Bengal, and operated by the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). Prior to the COVID-19 pandemic, 15,700 individuals were screened for DM and HTN, of whom 8506 aged 18 years or older were included in this study. Crude mortality rates (MR) per 1000 person-years (PYR) were estimated by age, sex, education, and household wealth quintile for individuals with DM/HTN compared to those without, both before and during the pandemic. A Cox proportional hazards model was used to examine differences in mortality risk during the pandemic between individuals with and without DM/HTN, adjusting for sociodemographic factors. Results Among the 8506 study participants, 2.7% (n = 232) had DM, 4.8% (n = 407) had HTN, less than 1% (n = 75) had both conditions and 6.6% (n = 564) had either condition. Among individuals without DM/HTN, the crude MR was 7.1 per 1000 PYR overall (6.9 before COVID-19, 7.5 during); among those with DM/HTN, the crude MR was 28.8 overall (21.2 before, 44.5 during). After adjusting for socio-demographic factors, mortality did not increase significantly during COVID-19 among individuals without DM/HTN. However, among those with DM/HTN, adjusted mortality risk during COVID-19 was nearly twice as high as in the pre-COVID-19 period (Hazard Ratio (HR) = 1.89; 95% CI: 1.22–2.91; p < 0.01). Conclusion The COVID-19 pandemic significantly increased all-cause mortality among individuals with DM or HTN in the rural sub-district of Chakaria in southeast Bangladesh on the coast of the Bay of Bengal through direct and indirect pathways.