Prognosis of asymptomatic hematuria and/or proteinuria in men. High prevalence of IgA nephropathy among proteinuric patients found in mass screening.
OBJECTIVE
To elucidate prognosis and prevalence of chronic renal diseases among proteinuric and/or hematuric subjects found in mass screening, a long-term follow-up study (6.35 years, range 1.03-14.6 years) was conducted on Japanese working men.


METHODS
A total of 772 subjects selected from 50,501 Japanese men aged 15-62 years were found to have asymptomatic hematuria (n = 404), concomitant hematuria and proteinuria (n = 155), and proteinuria (n = 213) during their annual urine examination and five consecutive urinalyses.


RESULTS
Hematuria patients showed significant improvements in urinary abnormalities as compared with both hematuria/proteinuria and proteinuria patients. Both hematuria/proteinuria patients with normotension and hematuria/proteinuria patients aged under 40 years showed significant improvements. During the follow-up period, 9.5% of the hematuria patients became hematuric/proteinuric. Hematuria/proteinuria patients had the highest risk of developing renal insufficiency. The presence of hypertension at detection of urinary abnormalities did not affect the renal function; however, if proteinuria appeared after the age of 40 years, these patients had a higher risk of developing renal insufficiency. The incidence of IgA nephropathy in the present subjects was as high as 143 cases per 1 million per year.


CONCLUSIONS
Detailed follow-up and definitive diagnosis of asymptomatic urinary abnormalities may raise the prevalence of IgA nephropathy worldwide.
Yamagata
Kunihiro
K
Institute of Clinical Medicine, University of Tsukuba, Japan. k-yamaga@md.tsukuba.ac.jp
Takahashi
Hideto
H
Tomida
Chie
C
Yamagata
Yoh
Y
Koyama
Akio
A
D000293:Adolescent; D000328:Adult; D002908:Chronic Disease; D018450:Disease Progression; D005500:Follow-Up Studies; D005921:Glomerulonephritis / Q000453:epidemiology; D005922:Glomerulonephritis, IGA / Q000453:epidemiology; D006417:Hematuria / Q000453:epidemiology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000473:pathology; D007674:Kidney Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011507:Proteinuria / Q000453:epidemiology*; D012044:Regression Analysis; D018570:Risk Assessment; D016482:Urinalysis