Adipose Tissue Insulin Resistance is Closely Associated with Metabolic Syndrome in Northern Chinese Populations

Figures & data

Table 1 Clinical Characteristics of Participants Categorized by Sex and Metabolic Syndrome

	Male			Female
	Control Group (n=26)	NMS Group (n=54)	MS Group (n=101)	Control Group (n=20)	NMS Group (n=26)	MS Group (n=85)
Age (years)	41.46 ± 7.22	48.98 ± 8.70 ^a	50.48 ± 7.73 ^a	48.35 ± 7.08	44.35 ± 9.99	47.04 ± 8.57
BMI (kg/m^2)	21.60 ±1.56	29.73 ± 3.60 ^a	29.92 ± 2.90 ^a	25.09 ± 3.36	30.36 ± 2.92 ^a	30.89 ± 2.87 ^a
WC (cm)	72.69 ± 5.33	90.31 ± 7.46 ^a	92.10 ± 7.34 ^a	82.58 ± 4.57	99.31 ± 7.47 ^a	100.96 ± 6.87 ^a
SBP (mmHg)	111.04 ± 15.57	131.72 ± 20.50 ^a	142.35 ± 21.33 ^ab	134.05 ± 25.65	139.38 ± 22.09	140.79 ± 18.33
DBP (mmHg)	72.38 ± 8.90	84.80 ± 10.84 ^a	89.22 ± 12.87 ^a	83.60 ± 13.21	93.31 ± 15.83	91.54 ± 11.01 ^a
ALT (U/L)	12.73 ± 4.00	25.50 ± 17.03 ^a	25.10 ± 13.95 ^a	23.00 ± 10.38	31.42 ± 18.58	42.02 ± 27.61 ^a
AST (U/L)	17.31 ± 4.23	23.46 ± 7.86 ^a	22.58 ± 8.58 ^a	23.30 ± 7.14	24.23 ± 6.12	27.18 ± 10.39
Cr (μmol/L)	68.39 ± 13.77	72.41 ± 10.79	69.62 ± 10.91	82.09 ± 15.41	91.08 ± 12.15	86.82 ± 15.91
UA (μmol/L)	173.68 ± 44.18	229.83 ± 52.99 ^a	239.57 ± 57.53 ^a	246.87 ± 53.12	359.85 ± 100.95 ^a	340.35 ± 77.33 ^a
TC (mmol/L)	4.29 ± 1.36	4.99 ± 0.95 ^a	5.12 ± 1.01 ^a	5.08 ± 0.87	5.04 ± 0.83	5.27 ± 0.90
TG * (mmol/L)	0.80 (0.53, 1.26)	1.14 (0.84, 1.52)	1.82 (1.35, 2.79) ^ab	1.22 (1.01, 1.65)	1.30 (0.89, 1.53)	2.45 (1.79, 3.60) ^ab
HDL-C (mmol/L)	1.45 ± 0.32	1.49 ± 0.28	1.19 ± 0.22 ^ab	1.41 ± 0.31	1.26 ± 0.21	1.08 ± 0.26 ^ab
LDL-C (mmol/L)	2.65 ± 1.06	3.10 ± 0.79	3.20 ± 0.82 ^a	3.17 ± 0.74	3.39 ± 0.74	3.22 ± 0.70
FFA (μmol/L)	453.01 ± 176.24	534.00 ± 184.39	657.33 ± 297.69 ^ab	578.07 ± 309.14	581.93 ± 214.10	799.18 ± 346.39 ^ab
FINS (mU/L)	5.84 ±6.64	9.58 ± 4.48 ^a	10.94 ± 5.64 ^a	5.67 ± 3.96	10.13 ± 5.73 ^a	13.92 ± 8.27 ^ab
FBG (mmol/L)	5.06 ± 0.27	5.32 ± 1.04	6.05 ± 1.56 ^ab	4.98 ± 0.38	5.27 ± 0.52	6.19 ± 1.73 ^ab
2h PBG (mmol/L)	5.33 ± 1.00	6.88 ± 2.23 ^a	9.56 ± 4.71 ^ab	5.19 ± 1.39	6.81 ± 2.23 ^a	9.65 ± 4.97 ^ab
Adiponectin (μg/mL)	20.99 ± 6.44	20.79 ± 6.26	17.33 ± 6.75 ^ab	18.59 ± 7.00	16.41 ± 6.13	13.67 ± 5.53 ^a
Adipo-IR *	2.16 (1.24, 3.18)	5.02 (2.55, 7.14) ^a	5.65 (3.51, 10.42) ^ab	2.32 (1.36, 3.63)	4.06 (2.78, 8.36) ^a	8.32 (5.10, 14.35) ^ab
HOMA-IR *	0.97 (0.66, 1.41)	2.14 (1.31, 3.01) ^a	2.57 (1.65, 3.80) ^ab	1.00 (0.81, 1.40)	2.17 (1.35, 3.58) ^a	3.12 (2.21, 5.23) ^ab
HOMA-AD *	52.96 (31.06, 69.67)	108.66 (64.05, 152.03) ^a	162.44 (94.10, 251.36) ^ab	56.48 (42.25, 131.30)	157.16 (70.19, 232.26) ^a	272.66 (145.84, 474.24) ^ab

Notes: ^aP < 0.05 compared with the control group. ^bP < 0.05 compared with the NMS group. *Variables were lg-transformed before analysis.

Abbreviations: NMS, nonmetabolic syndrome; MS, metabolic syndrome; BMI, body mass index; WC, waist circumference; SBP, systolic blood pressure; DBP, diastolic blood pressure; ALT, alanine transaminase; AST, aspartate transaminase; Cr, creatinine; UA, uric acid; TC, total cholesterol; TG, triglycerides; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; FFA, free fatty acid; FINS, fasting insulin; FBG, fasting blood glucose; 2h PBG, 2h-postprandial blood glucose; Adipo-IR, adipose tissue insulin resistance; HOMA-IR, homeostasis model assessment estimate of insulin; HOMA-AD, homeostasis model assessment adiponectin.

Figure 1 Sex differences of Adipo-IR (A and B), FINS (C and D), and FFA (E and F) in all subjects and subgroups. Adipo-IR, adipose tissue insulin resistance; FINS, fasting insulin; FFA, free fatty acids; Con, control group; NMS, nonmetabolic syndrome; MS, metabolic syndrome. ^a P < 0.05 compared with the control group. ^b P < 0.05 compared with the NMS group.

Table 2 Correlation Between Adipo-IR and Clinical Parameters in All Subjects, Male and Female Subjects

Parameters	All r (P-value)	Males r (P-value)	Females r (P-value)
Age (years)	−0.102 (0.073)	−0.211 (0.015)	0.002 (0.981)
BMI (kg/m^2)	0.430 (<0.001)	0.371 (<0.001)	0.434 (<0.001)
WC (cm)	0.480 (<0.001)	0.504 (<0.001)	0.399 (<0.001)
SBP (mmHg)	0.137 (0.016)	−0.054 (0.541)	0.212 (0.004)
DBP (mmHg)	0.203 (<0.001)	0.065 (0.462)	0.246 (0.001)
ALT (U/L)	0.490 (<0.001)	0.451 (<0.001)	0.453 (<0.001)
AST (U/L)	0.317 (<0.001)	0.248 (0.004)	0.292 (<0.001)
Cr (μmol/L)	0.095 (0.094)	−0.084 (0.342)	0.053 (0.479)
UA (μmol/L)	0.395 (<0.001)	0.335 (<0.001)	0.421 (<0.001)
TC (mmol/L)	0.199 (<0.001)	0.130 (0.139)	0.221 (0.003)
TG (mmol/L)	0.522 (<0.001)	0.574 (<0.001)	0.431 (<0.001)
HDL-C (mmol/L)	−0.323 (<0.001)	−0.279 (0.001)	−0.279 (<0.001)
LDL-C (mmol/L)	0.106 (0.062)	−0.026 (0.764)	0.176 (0.018)
FBG (mmol/L)	0.283 (<0.001)	0.353 (<0.001)	0.229 (0.002)
2h PBG (mmol/L)	0.385 (<0.001)	0.424 (<0.001)	0.362 (<0.001)
Adiponectin (μg/mL)	−0.347 (<0.001)	−0.380 (<0.001)	−0.257 (<0.001)
HOMA-IR	0.889 (<0.001)	0.887 (<0.001)	0.888 (<0.001)
HOMA-AD	0.815 (<0.001)	0.826 (<0.001)	0.803 (<0.001)

Notes: The results showed the correlation coefficients (P values). Bold indicates significant correlations at P < 0.05.

Abbreviations: BMI, body mass index; WC, waist circumference; SBP, systolic blood pressure; DBP, diastolic blood pressure; ALT, alanine transaminase; AST, aspartate transaminase; Cr, creatinine; UA, uric acid; TC, total cholesterol; TG, triglycerides; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; FFA, free fatty acid; FINS, fasting insulin; FBG, fasting blood glucose; 2h PBG, 2h-postprandial blood glucose; Adipo-IR, adipose tissue insulin resistance; HOMA-IR, homeostasis model assessment estimate of insulin; HOMA-AD, homeostasis model assessment adiponectin.

Figure 2 Multiple linear regression analysis of variables independently related to Adipo-IR in all subjects.

Abbreviations: Adipo-IR, adipose tissue insulin resistance; B, regression coefficients; 95% CI, 95% confidence interval; WC, waist circumference; TG, triglycerides; AST, aspartate transaminase; FBG, fasting blood glucose; Lg (Adipo-IR), base 10 logarithm of Adipo-IR.

Figure 3 Number of subjects with different metabolic diseases in the tertiles of Adipo-IR. ^a P < 0.05 compared with the lowest tertile. ^b P < 0.05 compared with the median tertile.

Abbreviations: Adipo-IR, adipose tissue insulin resistance; MS, metabolic syndrome.

Table 3 Logistic Regression Analysis of the Risk of MS in the Tertiles of Adipo-IR

Adipo-IR	Lowest OR (95% CI)	Median OR (95% CI)	Highest OR (95% CI)
Range (mU/L × mmol/L)	≤3.86	3.87–7.96	≥7.96
Univariate	1.00 (reference)	2.328 (1.333–4.056)	7.840 (4.112–14.951)
P		0.003	<0.001
Model 1	1.00 (reference)	1.801 (0.962–3.371)	5.455 (2.643–11.257)
P		0.066	<0.001
Model 2	1.00 (reference)	1.768 (0.855–3.655)	4.212 (1.768–10.039)
P	0.063	0.124	<0.001
Model 3	1.00 (reference)	1.566 (0.747–3.281)	3.758 (1.552–9.096)
P		0.235	0.003

Notes: Model 1: adjusted for age, sex, and BMI. Model 2: further adjusted for AST, SBP, UA, TC, and HDL-C based on Model 1. Model 3: further adjusted for adiponectin based on Model 2. Bold p-values indicate statistical significance (P <0.05).

Abbreviations: Adipo-IR, adipose tissue insulin resistance; OR, odds ratio; 95% CI, 95% confidence interval.

Figure 4 ROC curves of Adipo-IR, HOMA-IR, and HOMA-AD to distinguish between metabolic syndrome in male (A) and female (B) subjects in the study population.

Abbreviations: ROC, receiver operating characteristic; AUC, area under the curve; Adipo-IR, adipose tissue insulin resistance; HOMA-IR, homeostasis model assessment estimate of insulin; HOMA-AD, homeostasis model assessment adiponectin.