Sitagliptin as add-on therapy in insulin deficiency: biomarkers of therapeutic efficacy respond differently in type 1 and type 2 diabetes

Figures & data

Table 1 Clinical and laboratory characteristics in patients with type 1 and type 2 diabetes at baseline and final visit after combined therapy

Characteristic	Baseline	After treatment	P value
Type 1 diabetes
BMI, kg/m^2	26.5 ± 3.3	25.8 ± 3.4	<0.001
FPG, mmol/L	11.3 ± 4.8	10.5 ± 3.8	<0.5
Fructosamine, μmol/L	365 ± 53	339 ± 50	0.004
HbA1c, %	8.7 ± 1.3	8.7 ± 1.2	<0.5
LDL cholesterol, mmol/L	2.6 ± 0.8	2.3 ± 0.6	0.015
Insulin dose, U/kg/day	0.73 ± 0.36	0.60 ± 0.24	<0.001
Type 2 diabetes
BMI, kg/m^2	31.0 ± 4.4	30.7 ± 4.3	0.109
FPG, mmol/L	11.3 ± 3.8	9.2 ± 3.5	0.001
Fructosamine, μmol/L	371 ± 41	324 ± 41	<0.001
HbA1c, %	9.3 ± 0.9	8.6 ± 0.9	0.002
LDL cholesterol, mmol/L	2.9 ± 0.7	2.4 ± 0.8	0.008
Insulin dose, U/kg/day	0.51 ± 0.24	0.42 ± 0.21	<0.001

Notes: The values are expressed as mean ± standard deviation; comparison by paired t-test (two-tailed P value).

Abbreviations: BMI, body mass index; FPG, fasting plasma glucose; LDL, low-density lipoprotein.

Table 2 Clinical and laboratory characteristics in 23 patients with type 1 diabetes and 30 type 2 diabetes who had a complete clinical and laboratory evaluation at an intermediate visit between baseline and final visit

Characteristic	Baseline	After 21 ± 9 weeks	P value	After 49 ± 17 weeks	P value
Type 1 diabetes
BMI, kg/m^2	26.1 ± 3.2	25.7 ± 3.3	0.014	25.5 ± 3.3^a	0.004
FPG, mmol/L	11.0 ± 4.9	8.1 ± 5.5	0.008	10.3 ± 3.7	<0.5
Fructosamine, μmol/L	368 ± 55	327 ± 39	<0.001	341 ± 52	0.013
HbA1c, %	8.7 ± 1.4	8.0 ± 0.9	<0.001	8.7 ± 1.3^b	<0.5
LDL cholesterol, mmol/L	2.5 ± 0.6	2.3 ± 0.7	0.162	2.2 ± 0.5	0.049
Insulin dose, U/kg/day	0.72 ± 0.38	0.56 ± 0.24	<0.001	0.59 ± 0.25	0.001
Characteristic	Baseline	After 27 ± 12 weeks	P value	After 56 ± 14 weeks	P value
Type 2 diabetes
BMI, kg/m^2	31.2 ± 4.4	30.9 ± 4.6	0.142	30.8 ± 4.4	0.068
FPG, mmol/L	11.4 ± 3.9	9.5 ± 2.9	0.006	9.3 ± 3.4	0.002
Fructosamine, μmol/L	371 ± 42	313 ± 30	<0.001	324 ± 42	<0.001
HbA1c, %	9.3 ± 0.9	8.2 ± 0.8	<0.001	8.6 ± 0.9^b	0.002
LDL cholesterol, mmol/L	2.7 ± 0.7	2.5 ± 0.8	0.046	2.4 ± 0.8	0.007
Insulin dose, U/kg/day	0.51 ± 0.24	0.41 ± 0.22	<0.001	0.43 ± 0.21	<0.001

Notes: The values are expressed as mean ± SD; the two P value columns refer to the comparison by paired t-test (two-tailed P value) between intermediate or final visit, respectively, versus baseline visit; letter superscripts indicate significant differences (^a P < 0.05 and ^b P < 0.01) between final versus intermediate visit.

Abbreviations: BMI, body mass index; FPG, fasting plasma glucose; LDL, low-density lipoprotein.

Figure 1 Linear relationship between the decrease in LDL cholesterol levels (Δ LDL cholesterol) and the decrease in daily insulin requirement (Δ insulin dose) in patients with type 1 diabetes.

Abbreviation: LDL, low-density lipoprotein.