Puberty, IDDM, and Death in Japan

OBJECTIVE To investigate the impact of age at onset on the prognosis of childhood IDDM in Japan.

RESEARCH DESIGN AND METHODS The study population consisted of 987 prepubertal-onset and 345 pubertal-onset IDDM cases who were registered by two nationwide surveys and who were diagnosed between 1965 and 1979. The living status was identified as of 1 January 1990 with the ascertainment rate of 96.5%. Prognosis was evaluated by cause- and agespecific mortality rates and life-table analyses; in addition, an attained-age-matched case-control study was analyzed by conditional logistic regression.

RESULTS The adjusted mortality rates per 100,000 person-years for the pubertal-onset cases were significantly higher than those of the prepubertal-onset cases (835 [95% CI 573–1,168] vs. 391 [283–526]). Life-table analyses revealed that the survival rate of the pubertal-onset cases was lower than that of the prepubertal-onset cases for each observation period. Life-table analyses after the age of 15 years indicated that the prognosis of pubertal cases was almost the same as that of the prepubertal cases despite having a shorter duration of diabetes. The attained-age–matched case-control study indicated that the pubertal onset was a potent determinant of death.

CONCLUSIONS The prognosis of pubertal-onset IDDM was considerably poorer than that of prepubertal-onset IDDM.