Association of endothelin-1 and matrix metallopeptidase-9 with metabolic syndrome in middle-aged and older adults

Abstract

Background: Metabolic syndrome (MetS) contains a cluster of cardiovascular risk factors. People with MetS are more susceptible to cardiovascular disease, diabetes mellitus, and cancer. Endothelin-1 (ET-1) and matrix metallopeptidase-9 (MMP-9) have been implicated in the development of cardiovascular diseases, diabetes mellitus and cancers. This cross-sectional study aimed to examine the association of ET-1 and MMP-9 with MetS in middle-aged and older Hong Kong Chinese adults.

Methods: 149 adults aged 50 to 92 (n = 75 for non-MetS group and n = 74 for MetS group) were examined. All subjects were screened for MetS according to the diagnostic guideline of the United States National Cholesterol Education Program (NCEP) Expert Panel Adult Treatment Panel (ATP) III criteria. Serum levels of ET-1 and MMP-9 were measured. Independent t test was used to detect differences between non-MetS and MetS groups and between subjects with or without certain metabolic abnormality. The association of the serum concentration of MMP-9 and ET-1 with MetS parameters were examined by Pearson's correlation analysis.

Results: Serum level of ET-1 is higher in MetS-positive subjects and in subjects with high blood pressure, elevated fasting blood glucose, and central obesity. The serum concentration of MMP-9 is higher in subjects positively diagnosed with MetS and subjects with high blood pressure, elevated fasting blood glucose, low blood high-density lipoprotein-cholesterol (HDL-C), high blood triglycerides, and central obesity. Correlation analyses revealed that serum concentration of ET-1 is positively correlated to systolic blood pressure, waist circumference, fasting blood glucose, and age whereas it is negatively correlated to HDL-C. MMP-9 is positively correlated to systolic blood pressure, waist circumference, fasting blood glucose, and age whereas it is negatively correlated to HDL-C.

Conclusion: Serum ET-1 is higher in subjects with hypertension, hyperglycemia, central obesity or MetS. Serum MMP-9 is higher in subjects diagnosed with MetS or having either one of the MetS parameters. Both circulating levels of ET-1 and MMP-9 are correlated to systolic blood pressure, waist circumference, fasting blood glucose, HDL-C, and age. Further research is needed to fully dissect the role of ET-1 and MMP-9 in the development of cancers, diabetes and cardiovascular disease in relation to MetS.

Keywords: Cancer; Cardiovascular disease; Diabetes mellitus; ET-1; MMP-9; Metabolic syndrome.

Fig. 1

MetS parameters in subjects with or without MetS and metabolic abnormalities. a Systolic pressure in subjects with or without MetS. b Diastolic pressure in subjects with or without MetS. c Waist circumference in subjects with or without MetS. d Blood triglycerides in subjects with or without MetS. e HDL-C in subjects with or without MetS. f Fasting blood glucose in subjects with or without MetS. Data are expressed as mean ± standard deviation. The differences between two groups were detected by independent t-test. Statistical significance was accepted at p < 0.05

Fig. 2

Serum level of ET-1 in subjects with or without MetS and metabolic abnormalities. a Serum level of ET-1 in subjects with or without MetS. b Serum level of ET-1 in subjects with or without hypertension. c Serum level of ET-1 in subjects with or without central obesity. d Serum level of ET-1 in subjects with or without hypertriglyceridemia. e Serum level of ET-1 in subjects with or without dyslipidemia (low HDL-C). f Serum level of ET-1 in subjects with or without hyperglycemia. Data are expressed as mean ± standard deviation. The differences between two groups were detected by independent t-test. Statistical significance was accepted at p < 0.05

Fig. 3

Serum level of MMP-9 in subjects with or without MetS and metabolic abnormalities. a Serum level of MMP-9 in subjects with or without MetS. b Serum level of MMP-9 in subjects with or without hypertension. c Serum level of MMP-9 in subjects with or without central obesity. d Serum level of MMP-9 in subjects with or without hypertriglyceridemia. e Serum level of MMP-9 in subjects with or without dyslipidemia (low HDL-C). f Serum level of MMP-9 in subjects with or without hyperglycemia. Data are expressed as mean ± standard deviation. The differences between two groups were detected by independent t-test. Statistical significance was accepted at p < 0.05

Fig. 4

Correlation analysis of serum level of ET-1 to parameters of metabolic syndrome. a Correlation between serum level of ET-1 and systolic blood pressure. b Correlation between serum level of ET-1 and diastolic blood pressure. c Correlation between serum level of ET-1 and waist circumference. d Correlation between serum level of ET-1 and blood triglycerides. e Correlation between serum level of ET-1 and blood HDL-C. f Correlation between serum level of ET-1 and fasting blood glucose. g Correlation between serum level of ET-1 and age. Pearson’s correlation analysis was performed. Statistical significance was accepted at p < 0.05. Black diamond refers to the data of MetS-positive subjects. Open triangle refers to the data of MetS-negative subjects

Fig. 5

Correlation analysis of serum level of MMP-9 to parameters of metabolic syndrome. a Correlation between serum level of MMP-9 and systolic blood pressure. b Correlation between serum level of MMP-9 and diastolic blood pressure. c Correlation between serum level of MMP-9 and waist circumference. d Correlation between serum level of MMP-9 and blood triglycerides. e Correlation between serum level of MMP-9 and blood HDL-C. f Correlation between serum level of MMP-9 and fasting blood glucose. g Correlation between serum level of MMP-9 and age. Pearson’s correlation analysis was performed. Statistical significance was accepted at p < 0.05. Black diamond refers to the data of MetS-positive subjects. Open triangle refers to the data of MetS-negative subjects