Serum gamma-glutamyltransferase and the risk of hyperuricemia: a 6-year prospective study in Japanese men

Association between FTO (rs17817449) genetic variant, gamma-glutamyl transferase, and hypertension in Slovak midlife women

OBJECTIVES

This cross-sectional study investigates associations between the FTO rs 17817449 genetic variant, liver enzymes, and hypertension in Slovak midlife women.

METHODS

We assessed 576 Slovak women aged 39 to 65 years. The women were interviewed and examined during their medical examination at local Health Centers and then divided into subgroups according to their blood pressure status; 255 women with hypertension and 321 normotensive. The FTO genetic variant was detected by polymerase chain reaction-restriction fragment length polymorphism. Resultant data was analyzed by linear regression analysis and general linear models to adjust for risk factors associated with gamma-glutamyl transferase levels (GGT), including waist to hip ratio (WHR) and uric acid (UA).

RESULTS

A significant association between the FTO variant and GGT levels was observed in the hypertensive group after control for confounding covariates, including WHR and UA (p = .004). The predicted GGT level for GT/TT hypertensive carriers is 0.158 μkat/L higher than for GG carriers. Moreover, the two-way analysis of covariance revealed significant interaction between FTO effects and hypertension on logGGT levels (p = .042). Finally, hypertensive women with the T-allele had the highest estimated marginal mean value of logGGT at -0.39 μkat/L while the GG-genotype in both hypertensive and normotensive women had the lowest value at -0.54 μkat/L.

CONCLUSIONS

This study suggests that the FTO (rs17817449) variant is associated with higher serum GGT levels in hypertensive midlife women.

Uric acid to HDL cholesterol ratio is a strong predictor of diabetic control in men with type 2 diabetes mellitus

AIM

Despite it has some disadvantages, the most important marker of diabetic control is glycated hemoglobin (HbA1c). Uric acid to HDL cholesterol ratio (UHR) is a promising marker in metabolic syndrome. We aimed to compare UHR levels of well and poorly controlled type 2 diabetic male subjects, as well as healthy men, and to observe its correlation with other metabolic parameters.

METHODS

Male patients with T2DM that showed up in outpatient internal medicine clinics of our hospital were enrolled to the study. Diabetic subjects divided into two groups according to the level of HbA1c: well-controlled T2DM group (HbA1c < 7%) and poorly controlled T2DM group (HbA1c ≥ 7%). Third group was consisted of healthy subjects without any chronic diseases. UHR levels of the groups were compared.

RESULTS

The UHR levels of well and poorly controlled diabetics and control subjects were 12%±5%, 17%±6% and 9%±3%, respectively (p<.001). The UHR was significantly and inversely correlated with GFR and was significantly and positively correlated with waist circumference, body weight, body mass index, serum creatinine, fasting plasma glucose (FPG) and HbA1c levels.

CONCLUSION

UHR could serve as a promising predictor of diabetic control in men with T2DM, since it has significant association with HbA1c and FPG levels.

Association between serum gamma-glutamyl transferase and serum uric acid levels in Chinese females: A cross-sectional study

OBJECTIVE

To investigate the association between serum gamma-glutamyl transferase (GGT) levels and serum uric acid levels in middle-aged and elderly Chinese females.

METHODS

A cross-sectional population survey was performed in Luzhou, China (2014). Questionnaires, physical examinations and biochemical tests were conducted. Finally, we included 2486 females who were > 40 years old as participants. Multiple linear regression analysis was used to estimate the association of serum acid levels and other variables. Serum GGT levels were divided into four groups using the 25th, 50th and 75th percentiles as cut-off points. Finally, binary logistic regression analysis was used to investigate the association of different serum GGT quartiles with the risk of hyperuricemia.

RESULTS

The prevalence of hyperuricemia was 25.1% in the studied population and gradually increased across the serum GGT quartiles (P < 0.05). Binary logistic regression analysis showed that compared with subjects in the lowest quartile of serum GGT levels, the adjusted odds ratio (ORs) for uric acid in the highest quartile was 2.34 (95% confidence interval (CI), 1.68-3.28, P < 0.001),after corrections for TG, TC, HDL-C, LDL-C, creatinine (CR), GGT, AST, ALT, fasting plasma glucose (FPG), postprandial 2-h plasma glucose, hemoglobin A1c(HbA1c), age, BMI, SBP, DBP, waist-to-hip ratio and neck circumference (NC).

CONCLUSIONS

The serum GGT level is associated with hyperuricemia in middle-aged and elderly Chinese females.

Association between Sex Hormone and Blood Uric Acid in Male Patients with Type 2 Diabetes

The association between serum uric acid (SUA) level and sexual dysfunction in patients with diabetes is not well characterized. Type 2 diabetes mellitus (T2DM) causes metabolic disorders, including abnormal serum uric acid (SUA) levels. In this study, we enrolled 205 male patients with T2DM and investigated the relationship between sex hormone levels and SUA. Patients were divided into four groups based on SUA quartiles. On the other hand, based on the total testosterone (TT) level, patients were divided into three groups; SUA and other laboratory indices were determined. Increase in SUA level was significantly associated with decreased levels of TT, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, and increased levels of dehydroepiandrosterone, age, body mass index (BMI), waist circumference, glycated hemoglobin, serum creatinine, and HOMA-IR levels. SUA, waist circumference, BMI, and HOMA-IR showed a negative correlation with TT level, while age showed a positive correlation with TT level. SUA and body mass index were found to be risk factors for gonadal dysfunction. Therefore, we conclude that hypogonadism of male patients with T2DM is related to SUA level.

What does serum γ-glutamyltransferase tell us as a cardiometabolic risk marker?

γ-glutamyltransferase plays a key role in the synthesis and metabolism of extracellular glutathione, a major antioxidant in several defence mechanisms in the body. γ-glutamyltransferase is affected by environmental and genetic factors, and is raised when there is depletion of glutathione. Hence, it is a marker of oxidative stress. There is robust evidence that γ-glutamyltransferase even when values are within the reference interval is associated with increased cardiovascular and all-cause mortality in both sexes, in normal subjects and subjects with coronary artery disease, in the middle-aged and the elderly after adjusting for confounding factors. γ-glutamyltransferase even within the reference interval is associated with future presentation of type 2 diabetes, and the longitudinal increase in γ-glutamyltransferase activity is associated with increased risk of type 2 diabetes and cardiovascular mortality. γ-glutamyltransferase is associated with cardiovascular risk factors and metabolic syndrome. It has a prognostic value after a previous acute myocardial infarction and may be an indicator of adverse outcome in acute coronary syndromes and other chronic cardiac disorders. There is limited data about γ-glutamyltransferase and any association with peripheral arterial disease and also whether knowing γ-glutamyltransferase activity improves cardiovascular risk prediction beyond conventional risk factors. γ-glutamyltransferase is present in atherosclerotic lesions in the coronary and carotid arteries, and has a prooxidant role leading to the production of reactive oxygen species and atherosclerosis. Current reference intervals for γ-glutamyltransferase are inappropriate and need to be addressed. Some laboratories still use non- International Federation of Clinical Chemistry methods for estimation of γ-glutamyltransferase which are associated with lower results. Such laboratories should review their method and consider changing to the International Federation of Clinical Chemistry method.