Serum leptin levels and insulin resistance are associated with gallstone disease in overweight subjects

Table 1 Comparison of variables between cases and controls

Variable	Cases n = 97					Controls n = 190					P1
	Mean	SD	Median	Min	Max	Mean	SD	Median	Min	Max
Age (yr)	52.1	12.1	51.0	19.0	85.0	50.5	11.7	50	18.0	85	0.25
BMI (kg/m2)	28.2	5.5	27.7	18.6	54.9	27	3.9	26.9	19.0	40.1	0.12
Leptin (ng/mL)	18.2	44.7	10.2	1.9	431.0	11	6.5	9.5	1.3	40.7	0.11
Insulin (μU/mL)	11.1	7.4	9.1	1.8	35.7	9.4	6.3	7.6	2.0	43.7	0.07
T-chol (mmol/L)	5.43	1.09	5.46	2.48	8.38	5.38	1.03	5.4 3.	36	9.44	0.95
LDL (mmol/L)	3.44	0.85	3.36	1.11	5.61	3.49	0.85	3.41	1.60	6.13	0.73
HDL (mmol/L)	1.19	0.36	1.14	0.47	2.72	1.22	0.36	1.14	0.52	2.56	0.42
NHDL (mmol/L)	4.27	1.03	4.34	1.78	7.34	4.27	0.98	4.24	2.4	8.53	0.90
TGC (mmol/L)	1.89	1.15	1.7	0.43	6.78	1.71	0.96	1.46	0.06	7.38	0.18
HOMA-IR	2.9	2.2	2.3	0.4	11.7	2.4	1.8	1.8	0.4	13.2	0.04

¹Mann-Whitney U test. BMI, body mass index; T-chol, total cholesterol; LDL, low-density cholesterol; HDL, high-density cholesterol; NHDL, non-HDL cholesterol; TGC, triglycerides.

Table 2 Comparison of variables between cases and controls, stratified by BMI

Variable	BMI <30				P1	BMI ≥30				P1
	Cases n = 72		Controls n = 153			Cases n = 25		Controls n = 37
	No	%	No	%	No	%	No	%
Gender (male)	42	58.3	89	58.2	1.0	13	52.0	22	59.5	0.61
Age >50 yr	38	52.8	69	45.1	0.32	13	52.0	21	56.8	0.80
Leptin ≥9.78 ng/mL	37	51.4	61	39.9	0.11	16	64.0	30	81.1	0.15
Leptin					0.042					0.252
Tercile1<7.67 ng/mL	22	30.6	64	41.8		5	20.0	4	10.8
Tercile27.62.4 ng/mL	25	34.7	54		35		3 7	28.0	9	24.3
Tercile3>12.4 ng/mL	25	34.7	35	22.9		13	52.0	24	64.9
Insulin≥20μU/mL	9	12.5	0	0	<0.0001	4	16.0	12	32.4	0.24
HOMA-IR (>2.5)	29	40.3	42	27.5	0.07	15	60	24	64.9	0.79
T-chol≥6.21 mmol/L	19	26.4	45	29.4	0.75	6	24.0	6	16.2	0.52
LDL≥4.14 mmol/L3	19	27.1	40	26.7	1.0	5	21.7	7	18.9	1
HDL<1.03 mmol/L	27	37.5	50	32.7	0.55	8	32.0	13	35.1	1
NHDL ≥4.91 mmol/L	20	27.8	43	28.1	1.0	5	20.0	7	18.9	1
TGC ≥1.70 mmol/L	32	44.4	62	40.5	0.66	17	68.0	14	37.8	0.04

¹F exact test.

²χ² for linear trend. 3Five missing values for cases and 2 for controls. BMI, body mass index; T-chol, total cholesterol; LDL, low-density cholesterol; HDL, high density cholesterol; NHDL, non-HDL cholesterol; TGC, triglycerides

Table 3 Univariated analysis of conditional logistic regression, stratified by BMI

Variable	BMI <30			BMI ≥30
	OR	95%CI	P	OR	95%CI	P
Age (yr)	1.20	0.97-1.49	0.09	0.93	0.68-1.26	0.62
Leptin (ng/mL)	1.06	0.99-1.13	0.09	0.91	0.81-1.03	0.15
Insulin (μU/mL)	1.09	1.02-1.16	0.01	0.94	0.86-1.03	0.17
HOMA-IR	1.33	1.06-1.68	0.02	0.85	0.61-1.17	0.32
T-chol (mmol/L)	1.0	0.99-1.00	0.32	1.02	0.99-1.05	0.27
LDL (mmol/L)	1.0	0.99-1.01	0.51	1.01	0.98-1.05	0.39
HDL (mmol/L)	0.99	0.97-1.01	0.44	1.02	0.95-1.09	0.66
NHDL (mmol/L)	1.0	0.99-1.01	0.44	1.02	0.99-1.05	0.30
TGC (mmol/L)	1.0	1.0-1.0	0.86	1.0	1.0-1.01	0.3
Leptin ≥9.78 ng/mL	2.25	1.08-4.69	0.03	0.12	0.01-1.0	0.05
Leptin terciles (ng/mL)	1.67	1.03-2.69	0.04	0.14	0.02-0.98	0.05
Insulin ≥20 μU/mL Non		convergence		0.47	0.12-1.88	0.29
HOMA-IR >2.5	1.46	0.75-2.83	0.27	0.44	0.11-1.84	0.26
T-chol ≥6.21 mmol/L	0.86	0.42-1.74	0.67	3.88	0.38-39.5	0.25
LDL ≥4.14 mmol/L	1.06	0.55-2.04	0.87	1.50	0.36-630	0.58
HDL <1.03 mmol/L	1.26	0.66-2.41	0.49		Non convergence
NHDL ≥4.91mmol/L	1.07	0.54-2.13	0.84	0.78	0.07-8.88	0.84
TGC ≥1.7 mmol/L	1.09	0.60-1.99	0.77	3.03	0.76-12.1	0.12

OR, odds ratio; 95%CI, 95% confidence intervals; BMI, body mass index; T-chol, total cholesterol; LDL, low-density cholesterol; HDL, high density cholesterol; NHDL, non-HDL cholesterol; TGC, triglycerides.

Table 4 Multivariated analysis of conditional logistic regression, stratified by BMI

Variables	BMI <30			BMI ≥30
	OR	95%CI	P	OR	95%CI	P
HOMA-IR	1.31	1.04-1.66	0.02	No model founded
Leptin ≥9.78 ng/mL	2.1	1 0.99-4.53	0.05

OR, odds ratio; 95%CI, 95% confidence intervals.