Insulin action in adipose tissue in type 1 diabetes

Figures & data

Table 1 Clinical and analytical data for the study groups

	T1D patients (n = 9)	Controls (n = 8)
Body mass index (kg/m^2)	23.9 ± 5.0	23.8 ± 5.2
HbA1c (%)	6.5 ± 0.9a	4.3 ± 1.0
Fasting plasma glucose (mg/dL)	249 ± 100a	83 ± 7
Basal C-peptide (ng/mL)	0.5 ± 0.2a	2.0 ± 1.0
C-peptide at 5 minutes after glucagon (1 mg.IV) (ng/mL)	0.7 ± 0.3a	5.0 ± 0.9
% maximum ^125I-insulin binding	5.8 ± 0.4	6.4 ± 1.3
Basal U-(^14C)-D-glucose transport Fl/cel/s	71.4 ± 34	54.3 ± 38
Maximal U-(^14C)-D-glucose transport after 10^−7 mol/L insulin Fl/cel/s	135.4 ± 74	102.5 ± 47

Notes: Data are means ± standard deviation.

a P < 0.01.

Abbreviations: IV, intravenously; T1D, type 1 diabetes; HbA_1c, glycosylated hemoglobin.

Figure 1 Insulin action in the adipocyte: maximal insulin binding and basal and maximal glucose transport after stimulated insulin (10⁻⁷ mol/L) in type 1 diabetic patients with >5 years and ≤ of 5 years of diabetes.

Table 2 Insulin binding, basal glucose transport, and insulin-stimulated glucose transport in adipocytes from type 1 diabetic patients according to duration of disease

	T1D ≤ 5 years group	T1D > 5 years group	Control group
% maximum ^125I-insulin binding B/50,000 cells	6.2 ± 0.2a	5.4 ± 0.1	6.4 ± 1.3
Basal U-(^14C)-D-glucose transport Fl/cel/s	94.4 ± 24a,b	43.5 ± 21	54.3 ± 31
Maximal U-(^14C)-D-glucose transport insulin-stimulated glucose transport (10^−7 mol/L insulin) Fl/cel/s	184.2 ± 61a,b	74.2 ± 28	102.5 ± 47

Notes: Insulin binding is expressed as percentage of maximal ¹²⁵I-insulin binding; basal glucose transport is expressed as basal U-(¹⁴C)-D-glucose transport, and insulin-stimulated glucose transport as maximum insulin-stimulated (10⁻⁷ mol/L insulin) glucose transport.

a P < 0.05 versus type 1 diabetes >5 years group;

b P < 0.05 versus control group.

Table 3 Correlations between several clinical and analytical parameters and insulin action in adipocyte tissue in type 1 diabetes patients

	Length of diabetes (months)	HbA1c	Body mass index
% maximum insulin binding	r = −0.70	r = −0.33	r = −0.35
	P < 0.05	P < 0.34	P < 0.35
Basal glucose transport, Fl/cel/s	r = −0.87	r = −0.42	r = −0.51
	P < 0.01	P < 0.25	P < 0.12
Maximal glucose transport after insulin-stimulated glucose transport, Fl/cel/s	r = −0.88	r = −0.37	r = −0.38
	P < 0.01	P < 0.32	P < 0.30