BACKGROUND: We investigated whether parental history of type 2 diabetes mellitus (T2D) is associated with age, lifestyle, anthropometric factors, and clinical severity at the time of T2D diagnosis.

METHODS: We conducted a cross-sectional study based on the Danish Centre for Strategic Research in Type 2 Diabetes cohort. We examined the prevalence ratios (PR) of demographic, lifestyle, anthropometric, and clinical factors according to parental history, using Poisson regression adjusting for age and gender.

RESULTS: Of 2825 T2D patients, 34% (n = 964) had a parental history of T2D. Parental history was associated with younger age at diagnosis [adjusted (a)PR 1.66, 95% confidence interval: 1.19, 2.31) for age <40 years; aPR 1.36 (95% confidence interval: 1.24, 1.48) for ages 40-59 years] and with higher baseline fasting plasma glucose [≥7.5 mmol/L, aPR 1.47 (95% confidence interval: 1.20, 1.80)], and also tended to be associated with lower beta cell function. In contrast, patients both with and without a parental history had similar occurrence of central obesity [91% vs. 91%], weight gain ≥30 kg since age 20 [52% vs. 53%], and lack of regular physical activity [60% vs. 58%]. Presence of diabetes complications or comorbidities at T2D diagnosis was not associated with parental history.

CONCLUSIONS: The lack of an association between parental history and adverse lifestyle factors indicates that T2D patients do not inherit a particular propensity for overeating or inactivity, whereas patients with a parental history may have more severe pancreatic beta cell dysfunction at diagnosis.