End-stage renal disease and acute glomerulonephritis in Goajiro Indians

BACKGROUND: Goajiro Indians are a semi-nomad tribe that live on the Goajiro peninsula, in the northwestern part of Venezuela. We investigated the incidence of end-stage renal disease (ESRD) and post-streptococcal glomerulonephritis (PSGN) among Goajiros and to determine if it was increased and whether congenital endowment of low number of nephrons (as indicated by low birth weight) was a contributing factor in their predisposition to chronic renal failure (CRF). METHODS: The incidence of ESRD and the attack rate of poststreptococcal glomerulonephritis (PSGN) among Goajiros during the period December 1991 through December 1998 were evaluated from the records of the University Hospital, in Maracaibo, which is the referral center for Goajiro Indians. Demographic characteristics and birth weight were obtained from the records of the Regional Public Health Service. Subclinical reduction in renal functioning mass was investigated in 11 healthy Goajiros with a standardized tubular stress test that determines the increment in tubular secretion of creatinine (TSCr) resulting from the intravenous administration of a bolus of creatinine. RESULTS: The incidence of ESRD among Goajiros was 220 patients per million inhabitants per year, 1.7 times higher than the incidence for the country. The attack rate of post-streptococcal glomerulonephritis is nearly double among Goajiro Indians (2.9 +/- 1.3 cases/100,000 inhabitants/year) than in the general population in the neighboring Maracaibo city (1.5 +/- 0.3, P < 0.02). Low weight birth was common among Goajiros; as many as 23% of newborns weigh less than 1000 g. The stimulated TSCr in healthy Goajiros was 30% lower than in controls (P < 0.001). CONCLUSIONS: Goajiro Indians have a high incidence of ESRD. A high attack rate of PSGN and low nephron endowment in combination may be responsible, at least in part, for the increased risk of ESRD in this population.