UK study shows increasing proportion of younger adults with type 2 diabetes, with younger cases having a worse metabolic profile

New research presented at this year's Annual Meeting of the European Association for the Study of Diabetes (EASD) in Barcelona, Spain (16-20 September) shows that the proportion of younger adults being diagnosed with type 2 diabetes (T2D) has increased since the start of the century. The study is by Professor Sanjoy Ketan Paul, Chair in Clinical Epidemiology, Biostatistics & Health Services Research, Department of Medicine, University of Melbourne and Dr Digsu Koye, University of Melbourne, Australia and colleagues.

The changes over time, co-existing conditions (comorbidities) and long-term outcomes in young-onset T2D compared to older people with T2D have not been well studied. In this news study, the authors investigated temporal changes over time in young-onset T2D, risk factor control, comorbidities and the risk of developing atherosclerotic cardiovascular disease (ASCVD) and all-cause mortality separately by age groups at diagnosis.

Using nationally representative UK primary care electronic medical records, 370,854 people diagnosed with T2D from January 2000 were identified. The authors extracted data on anthropometric (physical measurements), clinical and laboratory measures and comorbidities (co-existing conditions) at diagnosis of T2D, and ASCVD and all-cause mortality during a median of seven years follow-up. The changes over time (temporal trend) in the proportion of people at diagnosis in the age groups 18-40, 41-50, 51-60, 61-70 and 71-80 were evaluated from 2000 to 2017. The temporal trend of rate / 1000 person years for ASCVD and all-cause mortality were calculated.

Of the 370,854 incident cases of T2DM identified, the mean age was 53 years, and 11% and 16% were in the 18-40 and 41-50 years age groups respectively. Proportion of people in these age groups marginally increased from 9.5% to 12.5% (18-40 years) and 14% to 17.5% (41-50 years) respectively over the 17 years of the study. Thus, in the UK today, around 1 in 8 new cases of T2D is in someone aged 18-40 years, compared to one in 10 in the year 2000.

The youngest group had significantly higher BMI (mean: 35 kg/m2, 71% obese), high blood glucose level (mean HbA1c: 8.6%; 58% with glycated haemoglobin HbA1c ? 7.5%) and levels of low density lipoprotein (bad) cholesterol (71% with LDL-C ? 100 mg/dL) compared to older people.

Furthermore, in the 18-40 years group about one-third had high blood pressure, 2% had ASCVD and 4% had chronic kidney disease. Almost a quarter 23% were identified as having increased cardiovascular risk without the history of ASCVD. In people in the age group 40-49 years at diagnosis, the mean BMI was 34 kg/m2 with 70% being obese, with 55% of patients with HbA1c of 7.5% or over. In the newly diagnosed patients aged 60-69 years, the mean BMI was down to 32 kg/m2 and 57% were obese, with only 38% with HbA1c over 7.5%. (SEE FULL TABLE LINK BELOW)

Rate of ASCVD was declining in all age groups between 2000 and 2006, followed by a stable and similar pattern for all age groups after 2007. The all-cause mortality rate declined over time by around 20% in those 60-69 years group and by around 30% in those 70-79 years group, but remained unchanged in the 18-59 years age groups. The average time to ASCVD or death was not different between high and low-risk status patients in the youngest people with T2DM.

The authors conclude: "The proportion of young-onset T2DM has increased from 2000 to 2017. Young people with T2DM have a higher cardiovascular risk factor burden. While cardiovascular morbidity and mortality risks have declined substantially over the years for older people with T2DM, they remain unchanged for younger people. Young-onset diabetes has a more aggressive phenotype compared to older-onset diabetes. More intense strategies are required to improve longer term cardiovascular and mortality outcomes in this population."