Association of Serum Leptin and Adiponectin Concentrations with Type 2 Diabetes Biomarkers and Complications Among Saudi Women

Figures & data

Table 1 Characteristics of Women with T2DM

Parameters	Diabetic n= 150	Reference Range
Age (years)^§	55.5±10.5	–
Smoking habit^#
Previous	20(13.3%)	–
Current	10(6.7%)	–
Never	120 (80%)	–
Anti-hypertriglyceridemic medication^#
Yes	55(36.7%)	–
No	95(63.3%)	–
Anti-hyperlipidemic medication^#
Yes	45(30%)	–
No	105(70%)	–
Anti-hypertensive medication^#
Yes	70(46.7%)	–
No	80(53.3%)	–
Duration of diabetes (years)^§	12.5±5.2	–
FBG (mmol/L)^§	7.1±0.87	3.89–5.50
HbA1c (%)^§	7.51±2.56	4.3–6.0
LDL-c (mmol/L)^§	2.97±0.95	2.59–4.11
HDL-c (mmol/L)^§	1.03±0.40	1.04–1.55
Total cholesterol (mmol/L)^§	5.98±0.84	5.2–6.2
Triglycerides (TG) (mmol/L)^§	2.89±2.64	1.7–2.2
BMI (kg/m2)^§	29.77±8.86	18.5–25.0
Waist circumference (WC) cm	112±12.16	< 88
Physical activity^§	8.9±2.26 (Middle activity)	Total score with a maximum value of 20
Leptin ng/mL^§	25.7±10.12	0.5–15.5
Adiponectin μg/mL^§	5±3.02	5–30
hs-CRP(mg/l)^§	17.9±6.17	<10
Fasting insulin (µU/mL)^§	7.9±5.55	< 25
Insulin Resistance (IR)^§	2.5±1.71	< 1.8
Insulin Sensitivity (IS)^§	0.4±0.11	>0.45
AIP^#,§
Low Risk	20(13.3%), 0.08±0.02	< 0.1
Middle Risk	60(40%), 0.15±0.08	0.1–0.24
High Risk	70(46.7%), 0.25±0.12	>0.24

Notes: ^#Numbers (%) and ^§Values were Mean ± standard deviation were shown. Bold values were considered abnormal values. References range obtained from Madinah Hospital labs at Madinah region, Saudi Arabia.

Table 2 Characteristics of Participants According to the Insulin Resistance (HOMA-IR) Index

Parameters	Low Tertile < 1.8	Middle Tertile> 1.9	Upper Tertile > 2.9	P-value
n= No. of samples	n=20(13.3%)	n=60(40%)	n=70(46.7%)	-
FBG (mmol/L)	6.44±0.27	6.92±0.77	7.90±0.83	0.04*
HbA1c (%)	6.55±2.66	6.61±2.62	6.85±3.26	>0.05
LDL-c (mmol/L)	2.79±0.85	2.85±0.73	3.01±0.97	>0.05
HDL-c (mmol/L)	1.04±0.45	1.0±0.20	0.99±0.50	0.03*
Total cholesterol (mmol/L)	4.78±0.83	4.98±0.86	5.88±0.89	>0.05
Triglycerides (TG) (mmol/L)	2.45±1.64	2.79±2.54	3.39±2.61	0.03*
BMI (kg/m2)	25.17±9.86	28.77±10.56	29.67±7.86	0.04*
Waist circumference (WC) cm	112±10.16	115±12.10	120±10.11	0.03*
Leptin ng/mL	20.7±11.12	23.9±9.12	26.7±11.9	0.02*
Adiponectin μg/mL	5±2.03	4.5±1.12	4.2±1.01	0.03*
hs-CRP(mg/l)	18.9±6.17	22.9±10.11	25.6±9.13	0.04*
Fasting insulin (mIU/L)	6.3±2.51	6.8±2.61	8.5±3.54	0.02*
Insulin Sensitivity (IS)	0.28±0.11	0.15±0.09	0.12±0.08	0.02*
AIP^#
Low Risk	5(25%)	13(21.7%)	2(2.9%)	>0.05
Middle Risk	11(55%)	20(33.3%)	29(41.4%)	>0.05
High Risk	4(20%)	27(45%)	39(55.7%)	0.05*

Notes: Data were expressed as the mean ± (SD) for continuous variables, P-value obtained from one-way ANOVA. *P≤0.05. ^#AIP data were presented as numbers (%).

Table 3 Characteristics of Participants According to BMI Categories

Parameters	Normal (18.5–25.0Kg/m^2)	Overweight (25.0–29.9Kg/m^2)	Obese (>30.0Kg/m^2)	P-value
n= No. of samples	n=23(15.3%)	n=62(41.3%)	n=65(43.4%)	–
FBG (mmol/L)	6.41±0.37	6.90±0.87	7.93±0.93	0.04*
HbA1c (%)	6.45±2.61	6.71±2.72	6.95±3.36	>0.05
LDL-c (mmol/L)	2.59±0.75	2.75±0.72	3.21±0.96	>0.05
HDL-c (mmol/L)	1.05±0.47	1.1±0.23	0.90±0.55	0.03*
Total cholesterol (mmol/L)	4.88±0.82	4.95±0.87	5.89±0.79	>0.05
Triglycerides (TG) (mmol/L)	2.55±1.61	2.89±2.51	3.79±2.31	0.03*
Waist circumference (WC) cm	99±10.12	118±11.10	125±15.12	0.03*
Leptin ng/mL	21.7±11.12	25.9±9.11	28.7±12.9	0.02*
Adiponectin μg/mL	4.88±2.01	4.2±1.15	3.6±1.01	0.03*
hs-CRP(mg/l)	18.8±5.17	24.9±10.13	26.6±9.16	0.04*
Fasting insulin (mIU/L)	6.4±2.33	6.9±2.41	8.9±3.64	>0.05
Insulin Resistance (IR)	1.8±0.73	2.2±0.85	3.1±0.87	0.03*
Insulin Sensitivity (IS)	0.51±0.41	0.45±0.29	0.32±0.18	0.02*
AIP^#
Low Risk	8(34.8%)	10(16.1%)	2(3.1%)	>0.05
Middle Risk	11(47.8%)	22(35.5%)	27(41.5%)	0.05*
High Risk	4(17.4%)	30(48.4%)	36(55.4%)	0.05*

Notes: Data were expressed as the mean ± (SD) for continuous variables, P-value obtained one-way ANOVA. *P≤0.05, and ^#AIP data was presented as numbers (%).

Table 4 Pearson’s Correlation Coefficients Between Leptin, Adiponectin, and Another Factor

Parameters	Leptin		Adiponectin
	r	P	r	P
FBG (mmol/L)	0.863	0.001**	−0.661	0.01*
HbA1c (%)	0.415	>0.05	−0.611	0.04*
LDL-c (mmol/L)	0.352	>0.05	0.332	>0.05
HDL-c (mmol/L)	−0.617	0.05*	0.627	0.04*
Total cholesterol (mmol/L)	0.413	0.06	0.423	0.07
Triglycerides (TG) (mmol/L)	0.852	0.02*	−0.751	0.04*
BMI (kg/m2)	0.635	0.03*	−0.573	0.05*
Waist circumference (WC) cm	0.321	>0.05	−0.569	0.05*
Fasting insulin (Uµ/mL)	0.422	0.07	0.321	0.06
Insulin Resistance (IR)	0.862	0.002**	−0.642	0.01*
Insulin Sensitivity (IS)	−0.554	0.02*	0.743	0.002**
hs-CRP (mg/l)	0.643	0.04*	0.313	>0.05
AIP	0.732	0.03*	−0.652	0.02*

Notes: P-values were obtained from Pearson’s correlation. * and ** indicate significance level at P≤0.05, and P≤0.001, respectively. Bold values indicate negative and inverse relation between leptin, adiponectin and other parameters.

Table 5 Multiple Linear Regression Analysis to Determine the Effects of Serum Leptin Level (Model 1) and Serum Adiponectin Level (Model 2) on T2DM Markers, Obesity Markers, and the Risk Factors for CVD

Variables	95% CI	B	P value
Model 5A :Linear regression between Leptin and IR, IS, BMI, WC, and AIP among women with T2DM
FBG (mmol/L)	1.964 to 5.104	4.365	0.003**
HDL-c (mmol/L)	−1.776 to −3.265	−2.854	0.02*
Triglycerides (TG) (mmol/L)	1.862 to 6.304	4.854	0.01*
BMI (kg/m2)	1.899 to 4.000	3.892	0.001**
Waist circumference (WC) cm	0.998 to 2.001	1.932	<0.001
Fasting insulin (Uµ/mL)	0.353 to 1.259	2.474	>0.05
Insulin Resistance (IR)	1.797 to 6.915	5.984	0.002**
Insulin Sensitivity (IS)	−2.997 to −7.205	−6.384	0.01*
hs-CRP (mg/l)	1.947 to 6.705	5.784	0.003**
AIP	1.392 to 4.055	3.974	0.02*
Adiponectin μg/mL	−1.219 to −5.150	−4.921	0.01*
R^2		0.655
Model 5B: Linear regression between Adiponectin and IR, IS, BMI, WC, AIP
FBG (mmol/L)	−1.159 to −3.190	−2.892	0.01*
HDL-c (mmol/L)	2.946 to 5.604	4.832	0.04*
Triglycerides (TG) (mmol/L)	1.803 to 2.159	1.372	0.06
BMI (kg/m2)	−2.6604 to −6.175	−5.952	0.03*
Waist circumference (WC) cm	−1.838 to −3.309	−2.912	0.04*
Fasting insulin (Uµ/mL)	0.793 to 1.135	1.354	>0.05
Insulin Resistance (IR)	−1.050 to −4.009	−3.762	0.02*
Insulin Sensitivity (IS)	2.136 to 4.013	3.339	0.03*
hs-CRP (mg/l)	0.561 to 1.627	1.329	>0.05
AIP	−1.541 to −3.177	−2.382	0.04*
Leptin ng/mL	−1.219 to −5.150	−4.921	0.01*
R^2		0.643

Notes: Serum leptin and adiponectin levels were used as the independent variable along with several dependent variables in Multiple Linear Regression analysis, Unstandardized coefficients (B), and 95% confidence intervals (CIs) were statistically significant at P ≤0.05* or ≤ 0.001**. R²: coefficient of regression: Unstandardized Coefficients; Value of R2 ranged from 0–1. Bold values indicate negative and inverse relationship between leptin and adiponectin.

Figure 1 Schematic chart representation of the influences of high leptin and low adiponectin levels on major factors involved in the complications of T2DM, such as CVD in Saudi females with high insulin resistance (IR) and high body mass index (BMI), triglycerides (TG), fasting blood glucose (FBG), high-density lipoprotein-cholesterol (HDL-C), insulin sensitivity (IS), C-reactive protein (hs-CRP), and waist circumstance (WC). (+) represented positive relation whereas (-) represented negative.