Effects of haemoglobin electrophoretic pattern and seasonal changes on urine concentration in young adult Nigerian males.

Renal concentrating capacity has been measured in healthy young adult Nigerian males with normal (AA) and abnormal (AS) haemoglobin types in both the dry and the wet seasons after 13 to 15 hours hydropenia respectively. The results show that, in the dry season, urine osmolality values in AA subjects are similar to those observed in Caucasians. They further confirm that renal concentrating capacity is impaired in persons with the S gene, and emphasize the limitations of the specific gravity test as a measure of renal concentrating capacity. In healthy AA subjects, the urine osmolality during the wet season is significantly less than in the dry season, even after longer periods of hydropenia. AS subjects, on the other hand, exhibit no seasonal variation in renal concentrating capacity.