γ-Glutamyl Transferase and High-Molecular-Weight Adiponectin Levels Are Synergistically Associated with Metabolic Syndrome and Insulin Resistance in Community-Dwelling Persons

Cross-sectional association between gamma-glutamyl transferase and hyperuricaemia: the China Multi-Ethinic Cohort (CMEC) study

OBJECTIVES

Several studies have demonstrated the association between gamma-glutamyl transferase (GGT) and hyperuricaemia, but little is known about such relation in less-developed ethnic minority regions.

DESIGN

We cross-sectionally analysed data from the China Multi-Ethnic Cohort (Yunnan region).

SETTING

Cross-sectional study.

PARTICIPANTS

22 020 participants aged 30-79 years from Han ethnicity, Yi ethnicity and Bai ethnicity.

OUTCOMES

The serum level of uric acid, GGT and other metabolic parameters were tested. Weight, height and blood pressure were measured. Smoking, drinking, ethnicity, education and medical history were obtained from questionnaires.

RESULTS

In the crude model, compared with the lowest quintile, the second, third, fourth and fifth quintiles of serum GGT exhibited a positive association with hyperuricaemia risk (OR=1.69, 2.90, 4.34 and 7.70, 95% CI=1.42 to 2.01, 2.47 to 3.42, 3.71 to 5.09 and 6.60 to 8.98, respectively, p-trend<0.0001). In fully adjusted model, compared with the lowest quintile, the second, third, fourth and fifth quintiles of serum GGT also exhibited a positive association with hyperuricaemia risk (OR=1.26, 1.68, 2.02 and 3.02, 95% CI=1.04 to 1.51, 1.40 to 2.00, 1.69 to 2.42 and 2.51 to 3.64, respectively, p-trend<0.0001). Logistic regression model was conducted separately in ethnic groups. Compared with first quintile, the highest GGT level were related to higher risk of hyperuricaemia in three ethnic groups (OR (95% CI): 2.89 (2.26 to 3.68), 2.81 (1.93 to 4.11) and 3.04 (1.91 to 4.84) for Han, Yi and Bai ethnicity, respectively, p-trend <0.0001). The relationship between GGT and hyperuricaemia was also observed in different age groups or gender groups.

CONCLUSIONS

High serum GGT level was related to a higher risk of hyperuricaemia in less-developed ethnic minority regions in China.

Serum Uric Acid to Creatinine Ratio Independently Predicts Incident Metabolic Syndrome Among Community-Dwelling Persons

BACKGROUND

Metabolic syndrome (MetS) is related to the increased risk of major cardiovascular disease. The link between high serum uric acid (SUA) and creatinine (Cr) levels is causally related to MetS and its components. However, whether renal function-normalized SUA [i.e., SUA to Cr ratio (SUA/Cr)] predicts incident MetS and its components remains inconclusive.

MATERIALS AND METHODS

We conducted a prospective cohort study designed as part of the Nomura study. The subjects comprised 447 men ages 68 ± 10 years and 625 women ages 68 ± 9 years from a rural village, and 155 (34.7%) men and 310 women (49.6%) had MetS at baseline. We found participants who underwent a similar examination 3 years later and analyzed the relationship between baseline SUA/Cr and incident MetS defined according to the modified criteria of the National Cholesterol Education Program-Adult Treatment Panel III (NCEP ATP III).

RESULTS

One hundred forty-nine (33.3%) men and 286 (45.8%) women had MetS after a 3-year follow-up. Multiple linear regression analysis was performed to evaluate the contribution of possible confounding factors for MetS. In women only, baseline SUA/Cr, as well as baseline number of MetS and age, was significantly and independently associated with the number of MetS components at follow-up. The multivariable-adjusted odds ratios (95% confidence interval) for incident MetS across three quartiles of baseline SUA/Cr (1st-2nd, 3rd, and 4th) were 1.00, 1.62 (0.97-2.69), and 2.07 (1.20-3.56), respectively. Furthermore, when subjects were stratified by age, estimated glomerular filtration rate (eGFR), and presence of baseline MetS, baseline SUA/Cr was also a significant and independent determinant for incident MetS in women with age ≥60 years, eGFR ≥70 mL/min/1.73 m², and presence of baseline MetS.

CONCLUSIONS

Baseline SUA/Cr was significantly associated with incident MetS among community-dwelling women.

Effect of berberine on the ratio of high-molecular weight adiponectin to total adiponectin and adiponectin receptors expressions in high-fat diet fed rats

OBJECTIVE

To assess the effects of berberine (BBR) on high-molecular weight (HMW) adiponectin and adiponectin receptors (adipoR1/adipoR2) expressions in high-fat (HF) diet fed rats.

METHODS

Forty Wistar male rats were randomly assigned into a normal diet fed group and three HF diet (fat for 45% calories) fed groups (n=10 for each group). All rats underwent 12 weeks of feeding. After 4 weeks feeding, rats in the two of three HF diet fed groups were treated with 150 mg·kg-1·day-1 BBR (HF+LBBR group) and 380 mg·kg-1·day-1 BBR (HF+HBBR group) by gavage once a day respectively for the next 8 weeks while the rats in other groups treated with vehicle (NF+Veh and HF+Veh). Body weight and food intake were observed and recorded on daily basis. At the end of 12 weeks, the blood, liver, epididymal fat tissues and quadriceps femoris muscles were collected. Fasting insulin, plasma fasting glucose, serum free fatty acid (FFA), total adiponectin and HMW adiponectin levels were measured by enzyme linked immunosorbent assay method. Glucose tolerance test (GTT) and insulin tolerance test (ITT) were performed to determine the insulinsensitizing. Meanwhile the homeostasis model assessment (HOMA) method was used to determine insulin resistance (HOMA-IR). The expressions of adipoR1, adipoR2 and adenosine monophophate activated protein kinase (AMPK) phosphorylation level in skeletal muscle and liver tissue were detected by Western blot. Liver and kidney toxicity were evaluated during treatment.

RESULTS

The body weight of rats in high- or low-dose BBR group reduced as well as HOMA-IR, FFA concentrations and fasting insulin levels decreased compared with HF+Veh group (P<0.05). BBR also increased the ratio of HMW to total adiponectin in high fat-fed rats compared with rats in the HF+Veh group. High- and low-dose BBR increased adipoR1 expression in skeletal muscle by over 6- and 2-fold (P<0.05), respectively, and high-dose BBR also increased adipoR2 expression in liver tissue by over 2-fold (P<0.05). BBR significantly increased AMPK phosphorylation in HF diet rats compared with normal diet rats (P<0.05). The ratio of HMW to total adiponectin was inversely correlated with HOMA-IR (r=-0.52, P=0.001). Meantime, no liver and kidney toxicity was found in high fat-fed rats that treated by BBR.

CONCLUSION

Berberine may improve insulin resistance by increasing the expression of adiponectin receptors and the ratio of HMW to total adiponectin.

Serum gamma-glutamyl transferase is associated with the elevated uric acid levels in normotensive Chinese adults

BACKGROUND

Although both serum gamma-glutamyltransferase (GGT) and uric acid are correlated with hypertension, studies on the association between serum GGT and uric acid in normotensive individuals are rare. In this study, we tried to reveal this relationship in normotensive Chinese adults.

METHODS

Four hundred seven normotensive adults were recruited. The subjects were divided into 3 subgroups according to serum GGT tertiles. Anthropometric parameters as well as systolic blood pressure (SBP), diastolic blood pressure (DBP), uric acid, GGT, alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood glucose, blood lipids, and fasting insulin were measured. Insulin resistance was assessed using HOMA-IR index.

RESULTS

Uric acid was increased in parallel with increasing serum GGT (P<0.001). After correction for age, sex, smoking and alcohol consumption, serum GGT was positively associated with uric acid (r=0.42, P<0.001), SBP (r=0.22, P<0.001), and DBP (r=0.19, P<0.001). When compared with lowest GGT tertile, the odds ratio of the middle tertile for the increased serum uric acid was 3.43 (95% CI, 1.39-8.47) and 7.29 (95% CI, 1.57-33.82) for the highest tertile after adjustment for age, sex, BMI, smoking, alcohol consumption, SBP, DBP, creatinine and HOMA-IR.

CONCLUSIONS

Serum GGT is strongly associated with the increased uric acid concentrations in normotensive Chinese adults.