Table 1.
Characteristics of the extracted studies (n = 10)
| Authors | Geographic region | Sample size | Age (years) | Sex (female %) | Follow up (years) | Proportion with obesity | Type 1 diabetes definition | Number of cases (%) |
|---|---|---|---|---|---|---|---|---|
| Carlsson et al. [25] | Europe | 38,800 | 40–59b | NR | 11 yearsa | 9.00% |
All of the following: (1) Self-reported diabetes (2) Insulin treatment within 6 months of diagnosis (3) Positive anti-GAD or C-peptide < 150 p/mol |
18 (0.05%) |
| Viner et al. [19] | Europe | 11,261 | 10c | 52.00% | 20c | 4.20% | Self-reported insulin-dependent diabetes before age 30 years | 47 (0.42%) |
| Harpsøe et al. [24] | Europe | 75,008 | 30.2 [27.4–33.3]b | 100% | 11.4 [10.2–12.5]b | 8.1d% | First hospital contact (primary diagnoses on in- and outpatient contacts) with ICD-8–10 type 1 diabetes codes obtained from the Danish national patient register | 144 (0.19%) |
| Tosur et al. [20] | North America, Australia, Europe | 4,873 | 11.7–12.4 [1.06–51.3]b | 52.20% | 1.0 [0.4–2.9]b | 15.2%e | ADA criteria, with the presence of antibodies | 591 (12.13%) |
| Nucci et al. [21] | North America, Australia, Europe | 2,149 | Birth cohort, measurement at different time points | 47.23% | 10c |
At age 2 years: 1.5% At age 10 years: 9.0% |
WHO, some with the presence of antibodies | 172 (8.00%) |
| Herzog et al. [23] | Europe | 132,207 | 43.89 (14.39)a | 48.25% | 18.87 (5.87)a | 34.26%e,f |
All of the following: (1) National registry record (2) One of the following: - Age at diagnosis < 30 years - Insulin prescription |
230 (0.17%) |
| Zucker et al. [15] | West Asia | 1,426,362 | 17.3 (0.5)b | 41.50% | 11.1 (5.9)a | 6.37% |
All of the following: (1) National registry record (2) Actively using short-acting insulin (3) Treatment with short-acting insulin initiated within 1 year of diagnosis (4) No history of treatment with oral anti-glycemic drugs (Antibodies in a sensitivity analysis) |
777 (0.05%) |
| Ferrannini et al. [16] | North America | 328 | 11 [8]b | 46.60% | 3.2 [2.8]b | N/Ag | ADA criteria, with the presence of antibodies | 115 (35.06%) |
| Steck et al. [18] | North America | 68 | NR | 52.90% | 5.7a | N/Ag | ADA criteria, with the presence of antibodies | 25 (36.78%) |
| So et al. [17] | North America, Australia, Europe | 3,856 | 13.27 (10.96)a | 47.50% | TrialNet’s Pathway to Prevention Study cohort | N/Ag | ADA criteria, with the presence of antibodies | 896 (23.24%) |
NR not reported, ADA American Diabetes Association. WHO World Health Organization, NHW non-Hispanic white, NHB non-Hispanic black. All BMI values are measured BMI unless indicated otherwise.
aMean, SD
bMedian [IQR / range]
cBirth cohort, included only those with full follow-up
dBMI was self-reported
eProportion was reported as overweight or obesity
fBMI was collected from medical records
gNot applicable, as BMI was not applied into categories