Table 1.

Characteristics by diabetes status

Characteristic			Probands with Diabetes	Siblings without Diabetes
n			48	47
Demographics
	Age at Exam (years)		17.1 (5.7)	15.4 (3.7)
	Tanner Stage (public 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
	Gender (%)
		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 Race	6.3	10.6
		Mixed Race	14.6	14.9
		Mexican Hispanic	6.3	6.4
Anthropometrics
	BMI Z-score⊥		0.8 (0.9)	0.4 (1.2)
	Percent Bodyfat		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)
	HbA1c (%)		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
	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 (%)I
		1-2 Injections/day	41.3
		3-4 Injections/day	37.0
		Pump	21.7
	Diabetes Type (%)§
		Type 1	75.0
		Type 2	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

HOMA2=Homeostatic Model Assessment 2 Numbers are means (standard deviations) and percentages To convert mg/dL to mmol/L for glucose, multiply by 0.055; to convert μU/mL to pmol/L for insulin, multiply by 6.0

^*p<0.05;

^**p<0.0001

^⊥BMI was transformed into Z-scores using CDC Growth Chart (≤20 years old) and NHANES III (>20 years old) age and sex-matched reference data

^ISubgroup using insulin, n=46

^§Diabetes type based on C-peptide levels, presence of diabetes antibodies, diabetes treatment, symptoms off insulin, and duration

^¶Insulin resistant criterion based on fasting insulin HOMA2: if age≤18 years, insulin resistant=HOMA2 ≥3.2 if age>18 years, insulin resistant=HOMA2 ≥2.5