Does seasonality of births in diabetes mellitus reflect pathogenetic differences?
This study indicates that the seasonality of births of patients with DM1 and DM2 has occurred in their adolescence or adulthood.



Patients with Diabetes mellitus type 2 (DM2) with the maturity onset have different seasonal birth patterns from those with Diabetes mellitus type 1 (DM1) with the maturity onset, or DM1children.



Monthly numbers of births of 81 and 236 children with DM1 and DM2, respectively, in adolescent or adult age, were adapted to different actual length of calendar months. The 12- and 6-month rhythm was tested using the cosinor regression with 95% confidence interval versus the hypothesis of null seasonality.



Regarding DM1 with maturity onset, annual and semiannual rhythm was significant in both genders, with the increase in birth numbers from November to January and decrease in March, April and August. In DM2, only female data displayed a significant annual rhythm, with an increase in birth from April to August and decrease from October to December.  CONCLUSION: The birth seasonality related to DM1 in adolescent or adult age appears to be reciprocal, compared to DM1 in childhood. For DM2, the seasonality of births was found only in females. The increase in female fecundity seems to be related to an increase in the risk of DM2 in female offspring. The outcomes could help in identifying environmental and endogenous factors related to seasonality cycle (Tab. 1, Fig. 1, Ref. 18).
M
M
Mikulecky
Z
Z
Rausova
L
L
Dedik
V
V
Mojto
D000293:Adolescent; D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis* / Q000453:epidemiology*; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D011336:Probability; D012621:Seasons; D012737:Sex Factors; D018154:Slovakia; D013223:Statistics as Topic
adulthood onset; birth seasonality; diabetes mellitus type 1; diabetes mellitus type 2.