A comparison of chronic kidney risk among returnee Nepalese migrant workers in the countries of the Gulf and Malaysia and non-migrants in Nepal: a population-based cross-sectional study

There have been increasing concerns about the possible high prevalence of chronic kidney disease (CKD) among returnee Nepalese migrant workers from the Gulf countries and Malaysia. This population-based cross-sectional survey primarily aimed to examine the prevalence of kidney health risks of Nepalese recent migrants compared to non-migrants from the same community. We conducted a cross-sectional survey of 1438 participants from Dhanusha district (718 recent migrants and 720 non-migrants (including historic migrants)). Recent migrants (all sexes) aged 18 years or above who had stayed for at least two years in six countries of the Gulf region or Malaysia in any occupation and had returned in the past 12 months were included. We used the core questionnaire and protocol for the Disadvantaged Populations eGFR Epidemiology Study (DEGREE) and added questions on migration. All recent migrants were male and they were compared to male historic migrants, male non-migrants, and female non-migrants. Only 6 (0.4%) cases of eGFR < 60mL/min/1.73m2 were identified overall. The prevalences of eGFR < 60mL/min/1.73m2 were 0.4% (95% CI: 0.08 to 1.2), 0.5% (95% CI: 0.01 to 2.6), 1.2% (95% CI: 0.1 to 4.2%), and zero in male recent migrants, male historic migrants, male non-migrants, and female non-migrants, respectively. The prevalence of high proteinuria (> 30 mg/g) was lowest among male recent migrants at 7.7% (95% CI: 5.8 to 9.8) and highest among female non-migrants at 10.5% (95% CI: 7.5 to 14.3). In the adjusted multiple regression model, male recent migrants had a statistically nonsignificant, slightly reduced mean difference in eGFR of -0.8 mL/min/1.73m2 (95% CI: -3.6 to 2.0) compared to male non-migrants. A separate adjusted model among male recent migrants showed a strong association between reduced mean eGFR and older age, occupation as a security guard, current or past smokers, and ethnicity (Terai Dalits and Muslims). This study found a low prevalence of eGFR < 60mL/min/1.73m2 in Nepalese recent migrants. There were no associations of mean eGFR by migration status despite male migrants being exposed to risk factors for kidney disease. Nonetheless, this study indicated that specific sub-groups of Nepalese migrants mainly those working as security guards and from certain ethnicities could be at higher risk. These require further investigations.