Rationale, description and baseline findings of a community-based prospective cohort study of kidney function amongst the young rural population of Northwest Nicaragua

Abstract

BackgroundAn epidemic of Mesoamerican Nephropathy (MeN) is killing thousands of agricultural workers along the Pacific coast of Central America, but the natural history and aetiology of the disease remain poorly understood. We have recently commenced a community-based longitudinal study to investigate Chronic Kidney Disease (CKD) in Nicaragua. Although logistically challenging, study designs of this type have the potential to provide important insights that other study designs cannot. In this paper we discuss the rationale for conducting this study and summarize the findings of the baseline visit.MethodsThe baseline visit of the community-based cohort study was conducted in 9 communities in the North Western Nicaragua in October and November 2014. All of the young men, and a random sample of young women (aged 18–30) without a pre-existing diagnosis of CKD were invited to participate. Glomerular filtration rate (eGFR) was estimated with CKD-EPI equation, along with clinical measurements, questionnaires, biological and environmental samples to evaluate participants’ exposures to proposed risk factors for MeN.ResultsWe identified 520 young adults (286 males and 234 females) in the 9 different communities. Of these, 16 males with self-reported CKD and 5 females with diagnoses of either diabetes or hypertension were excluded from the study population. All remaining 270 men and 90 women, selected at random, were then invited to participate in the study; 350 (97%) agreed to participate. At baseline, 29 (11%) men and 1 (1%) woman had an eGFR <90 mL/min/1.73 m2.ConclusionConducting a community based study of this type requires active the involvement of communities and commitment from local leaders. Furthermore, a research team with strong links to the area and broad understanding of the context of the problem being studied is essential. The key findings will arise from follow-up, but it is striking that 5% of males under aged 30 had to be excluded because of pre-existing kidney disease, and that despite doing so 11% of males had an eGFR <90 mL/min/1.73 m2 at baseline.Electronic supplementary materialThe online version of this article (doi:10.1186/s12882-016-0422-4) contains supplementary material, which is available to authorized users.

Decline in Kidney Function among Apparently Healthy Young Adults at Risk of Mesoamerican Nephropathy

“…The rationale and description of the study design have been published elsewhere. 20 Briefly, this was a 2-year longitudinal, community-based study following 350 participants ages 18-30 years old in the Leon and Chinandega regions of Nicaragua (Figure 1). After engagement work, we performed a census of all adults ages 18-30 years old in nine rural communities.…”

“…After exclusion of 4% of the potential participants because of self-reported CKD, diabetes, or hypertension, 350 participants (of the 360 invited after random selection of eligible women; 97%) were included in the study. 20 Overall, participants attended a total of 1581 study visits over the 2-year follow-up (92% of planned visits). Two participants died from ESRD during the study period.…”

Environmental exposures in young adults with declining kidney function in a population at risk of Mesoamerican nephropathy

“…The study rationale, design and baseline findings have been reported elsewhere (16,17). Briefly this was a population-representative, community-based follow-up study recruiting 350 men and women (ratio 3:1) aged 18-30 years without self-reported CKD or traditional CKD risk factors (diabetes or hypertension).…”

“…Since 2014, our team has been conducting the first prospective community-based cohort study investigating the evolution and aetiology of MeN. The study initially recruited 350 healthy men and women (3:1 ratio), from 9 rural communities in north-western Nicaragua (16). Participants were invited to follow-up visits every 6 months (before and immediately after the sugarcane harvest).…”

“…Participants were invited to follow-up visits every 6 months (before and immediately after the sugarcane harvest). A rapid decline in kidney function was observed in approximately 10% of males and 3% of women over the first 2 years (16).…”