Characteristics by diabetes status
| Characteristic . | Probands with diabetes . | Siblings without diabetes . |
|---|---|---|
| n | 48 | 47 |
| Age at exam (years) | 17.1 ± 5.7 | 15.4 ± 3.7 |
| Tanner stage (pubic hair) (%) | ||
| 1 | 4.2 | 14.9 |
| 2 | 8.3 | 6.4 |
| 3 | 18.7 | 8.5 |
| 4 | 31.3 | 29.8 |
| 5 | 37.5 | 40.4 |
| Sex (%) | ||
| Female | 52.1 | 40.4 |
| Male | 47.9 | 59.6 |
| Race/ethnicity (%) | ||
| Non-Hispanic white | 33.3 | 44.7 |
| Non-Hispanic black | 39.5 | 23.4 |
| Other | 6.3 | 10.6 |
| Mixed | 14.6 | 14.9 |
| Mexican Hispanic | 6.3 | 6.4 |
| Anthropometrics | ||
| BMI Z score* | 0.8 ± 0.9 | 0.4 ± 1.2 |
| Body fat (%) | 27.5 ± 10.0† | 22.3 ± 11.7 |
| Waist circumference (cm) | 78.7 ± 13.7 | 74.0 ± 13.4 |
| Blood measurements | ||
| Fasting glucose (mg/dl) | 199.8 ± 101.2‡ | 90.1 ± 6.9 |
| A1C (%) | 8.6 ± 2.0‡ | 5.1 ± 0.3 |
| Fasting C-peptide (nmol/l) | 0.3 ± 0.4‡ | 0.7 ± 0.4 |
| Absent C-peptide (%) | 66.7 | |
| Diabetes duration (years) | 7.7 ± 6.1 | |
| Age at diagnosis (years) | 9.4 ± 3.7 | |
| Diabetes treatment (%) | ||
| Insulin only | 91.6 | |
| Insulin and pills | 4.2 | |
| Pills only | 4.2 | |
| Insulin therapy (%)§ | ||
| 1–2 injections/day | 41.3 | |
| 3–4 injections/day | 37.0 | |
| Pump | 21.7 | |
| Diabetes type (%)‖ | ||
| Type 1 diabetes | 75.0 | |
| Type 2 diabetes | 16.7 | |
| Mixed | 8.3 | |
| Insulin resistance | ||
| Fasting insulin (μU/ml) | 9.5 ± 10.1 | |
| HOMA2 (using fasting insulin) | 1.2 ± 1.2 | |
| Insulin resistant (%)¶ | 4.3 |
| Characteristic . | Probands with diabetes . | Siblings without diabetes . |
|---|---|---|
| n | 48 | 47 |
| Age at exam (years) | 17.1 ± 5.7 | 15.4 ± 3.7 |
| Tanner stage (pubic hair) (%) | ||
| 1 | 4.2 | 14.9 |
| 2 | 8.3 | 6.4 |
| 3 | 18.7 | 8.5 |
| 4 | 31.3 | 29.8 |
| 5 | 37.5 | 40.4 |
| Sex (%) | ||
| Female | 52.1 | 40.4 |
| Male | 47.9 | 59.6 |
| Race/ethnicity (%) | ||
| Non-Hispanic white | 33.3 | 44.7 |
| Non-Hispanic black | 39.5 | 23.4 |
| Other | 6.3 | 10.6 |
| Mixed | 14.6 | 14.9 |
| Mexican Hispanic | 6.3 | 6.4 |
| Anthropometrics | ||
| BMI Z score* | 0.8 ± 0.9 | 0.4 ± 1.2 |
| Body fat (%) | 27.5 ± 10.0† | 22.3 ± 11.7 |
| Waist circumference (cm) | 78.7 ± 13.7 | 74.0 ± 13.4 |
| Blood measurements | ||
| Fasting glucose (mg/dl) | 199.8 ± 101.2‡ | 90.1 ± 6.9 |
| A1C (%) | 8.6 ± 2.0‡ | 5.1 ± 0.3 |
| Fasting C-peptide (nmol/l) | 0.3 ± 0.4‡ | 0.7 ± 0.4 |
| Absent C-peptide (%) | 66.7 | |
| Diabetes duration (years) | 7.7 ± 6.1 | |
| Age at diagnosis (years) | 9.4 ± 3.7 | |
| Diabetes treatment (%) | ||
| Insulin only | 91.6 | |
| Insulin and pills | 4.2 | |
| Pills only | 4.2 | |
| Insulin therapy (%)§ | ||
| 1–2 injections/day | 41.3 | |
| 3–4 injections/day | 37.0 | |
| Pump | 21.7 | |
| Diabetes type (%)‖ | ||
| Type 1 diabetes | 75.0 | |
| Type 2 diabetes | 16.7 | |
| Mixed | 8.3 | |
| Insulin resistance | ||
| Fasting insulin (μU/ml) | 9.5 ± 10.1 | |
| HOMA2 (using fasting insulin) | 1.2 ± 1.2 | |
| Insulin resistant (%)¶ | 4.3 |
Data are means ± SD or percent. To convert milligrams per deciliter to millimole per liter for glucose, multiply by 0.055; to convert microunits per milliliter to picomole per liter for insulin, multiply by 6.0.
BMI was transformed into Z scores using the Centers for Disease Control and Prevention Growth Chart (age ≤20 years) and National Health and Nutrition Examination Survey (NHANES) III (age >20 years) age- and sex-matched reference data.
P < 0.05.
P < 0.0001.
Subgroup using insulin, n = 46.
Diabetes type based on C-peptide levels, presence of diabetes antibodies, diabetes treatment, symptoms while off of insulin, and duration.
Insulin resistant criteria based on fasting insulin HOMA2: 1) if age ≤18 years, insulin resistance defined as HOMA2 ≥3.2 and 2) if age >18 years, insulin resistance defined as HOMA2 ≥2.5.