Male predominance of Type 1 (insulin-dependent) diabetes mellitus in young adults: results from a 5-year prospective nationwide study of the 15?34-year age group in Sweden

Abstract

The incidence of diabetes mellitus in Sweden in the 15-34 year age group was prospectively studied on a nationwide basis, beginning 1 January 1983. A total of 1,214 male and 720 female cases of newly-diagnosed (excluding gestational) diabetes were reported over a 5-year period. This corresponds to an incidence of 20.5 per 100,000/year in male subjects and 12.7 per 100,000/year in female subjects. Most cases were classified as Type 1 (insulin-dependent) diabetes, with an incidence of 15.9 in males and 8.6 in females. The incidence of Type 1 diabetes decreased gradually with age, while the incidence of Type 2 (non-insulin-dependent) diabetes increased. A male predominance was found in all age groups, with a male-to-female ratio of 1.8:1 for Type 1 diabetes and 1.3:1 for Type 2 diabetes. Maximum blood glucose concentration at diagnosis was significantly higher in males than in females in both Type 1 and Type 2 diabetic subjects. In contrast, the percent desirable weight was significantly higher in females, both in Type 1 and Type 2 diabetic subjects. The difference in diabetes incidence therefore cannot be attributed to any methodological error. The present finding of a marked male predominance after puberty in Type 1 diabetes in an ethnically quite homogeneous population supports the hypothesis that environmental risk factors and life-style are important for the development of the disease.

HLA-DQB1 genotypes, islet antibodies and beta cell function in the classification of recent-onset diabetes among young adults in the nationwide Diabetes Incidence Study in Sweden

“…However, logistic regression analysis showed that the associations between gender and age at onset to the types of islet antibodies were not related to risk HLA-DQB1 genotypes, as indeed previously shown [39]. Thus, the well known increased incidence of type 1 diabetes among young adult men [40][41][42][43], as also demonstrated in our study, does not seem to be HLA-DQB1 related, but being an effect of gender in itself. As emphasized by our finding that ketonuria and diabetic symptoms were clearly associated with male gender.…”

Incidence of Type I diabetes mellitus in children and young adults in the province of Upper Austria, 1994 –1996

“…The numbers could still be an underestimate as all patients not initially put on continuous insulin therapy were excluded and follow-up of uncertain cases was not possible. Similar high proportions of incident rates in young adults have been reported in Italy [12], in Poland [13], Belgium [11], Norway [9] and Sweden [10]. In accordance with several other studies [9±12, 14], we found a striking male predominance in the age group 20 years or older, whereas during childhood and adolescence the male-to-female ratio was almost the same as the background population.…”

The epidemiology of Type 1 diabetes mellitus is not the same in young adults as in children

“…A number of studies have reported a strong male preponderance in the incidence of Type 1 diabetes in adults [18,19,20,21,22,23,24,25,26,27]. In this respect young adults differ from children, for overall sex-specific differences in children are slight, although high-incidence populations tend to show male preponderance, and low-incidence populations (mostly non-European) show female preponderance [34].…”

“…Adult cases are characterised by a reduced frequency of HLA susceptibility haplotypes, as compared with children [1,16,17], and overall have less acute symptoms than children [1]. Male predominance is a further, unexplained feature of Type 1 diabetes in young adults [18,19,20,21,22,23,24,25,26,27]. This is in marked contrast to most other common immune-mediated conditions, which are typified by female preponderance [28].…”