Table 2.

Fasting C-peptide levels (nmol/l), per BMI group (kg/m²), and age (years) in adults with newly diagnosed diabetes. Values are mean±s.d., median, min–max.

		C-peptide, fasting					Age
BMI group		n	Autoimmune	n	Non-autoimmune	P Ai vs non-Ai	Autoimmune	Non-autoimmune	P Ai vs non-Ai
A	<20	7	0.20±0.06	29	1.03±0.64	<0.002	35.6±8.1	63.4±19.8	<0.001
			0.22, 0.13–0.31		1.0, 0.19–3.60		32.0, 26–50	69.0, 26–95
B	20 to <25	20	0.48±0.40	255	1.38±1.1	<0.0001	51.7±17.4	71.7±13.9	<0.0001
			0.36, 0.13–1.80		1.0, 0.13–8.30		52.0, 22–77	75.0, 23–94
C	25 to <30	21	1.09±0.38	440	1.36±0.8	NS	65.1±11.7	66.7±12.3	NS
			1.20, 0.52–1.80		1.20, 0.13–7.80		65.0, 40–82	67.0, 31–94
D	30 to <35	6	0.91±0.67	250	1.47±0.7	<0.04	60.3±13.8	62.7±13.3,	NS
			1.15, 0.25–1.80		1.30, 0.44–5.30		65.5, 43–73	63.0, 21–96
E	≥35	4	0.61±0.32	126	1.62±0.8	<0.02	42.3±14.5	59.1±13.9	0.04
			0.51, 0.35–0.96		1.50, 0.13–6.40		42.0, 28–57	58.0, 23–93
	All	58	0.76±0.53	1100	1.39±0.84	<0.0001	55.1±16.9	66.1±14.0	<0.0001
			0.62, 0.13–1.9		1.20, 0.13–8.3		55.0, 22–82	67.0, 21–100

Ai, autoimmune; non-Ai, non-autoimmune.