Subcutaneous adipose tissue protects against high BP, triglycerides
There is a longitudinal and positive correlation between visceral adipose tissue (VAT) area and the risk of incident metabolic syndrome (MS), shows a recent study from Korea. In contrast, subcutaneous adipose tissue (SAT) appears to protect against individual components of MS, such as high blood pressure (BP) and triglycerides.
“[T]he baseline SAT area was higher in subjects who had a reduced risk of some individual components of MS (high BP, fasting glucose) than in subjects who did not have a reduced risk, regardless of their baseline VAT area,” said researchers.
In the study sample of 1,964 individuals without baseline MS and who underwent routine health screenings over 5 years, 16.1 percent (n=317) developed MS over a median 4.5 years of follow-up. Fasting glucose and cholesterol levels, and VAT and SAT were all significantly higher in those who developed incident MS (p<0.001 for all). [Sci Rep 2017;7:10955]
Dividing the participants into quintiles of VAT showed a dose-dependent and positive association between VAT area and MS incidence.
Specifically, fully adjusted models revealed that those in the third (hazard ratio [HR], 2.57; 95 percent CI, 1.60 to 4.13; p<0.001), fourth (HR, 3.34; 2.07 to 5.39; p<0.001) and fifth (HR, 3.73; 2.22 to 6.28; p<0.001) quintiles had significantly higher risks of MS than those in the first quintile.
Every one standard-deviation (SD) increase in VAT area also significantly impacted the incidence of various MS components such as high BP (HR, 1.24; 1.04 to 1.48; p=0.07 for trend), high fasting glucose (HR, 1.26; 1.07 to 1.47; p=0.003 for trend) and high triglycerides (HR, 1.55; 1.31 to 1.83; p<0.001 for trend).
“VAT is known to play a significant role in MS through various pathways. Ectopic VAT accumulation can cause dysfunctional alterations in adipose tissue, such as free fatty acid metabolism changes and cellular hypoxia,” explained researchers. [Circulation 2011;124:1996-2019; Phys Rev 2013;93:1-21]
Similarly, every one SD increase in SAT area increased the risk of low high-density lipoprotein (HDL) cholesterol (HR, 1.24; 1.08 to 1.43; p=0.001 for trend). Interestingly, however, every one SD increase in SAT area showed protective effects against the incidence of high fasting glucose (HR, 0.89; 0.74 to 1.06), high BP (HR, 0.86; 0.69 to 1.07) and high triglycerides (HR, 0.94; 0.77 to 1.13).
“The marginal effect of SAT on metabolic abnormalities in our study may be explained by the different effects of deep SAT and superficial SAT. Further studies are needed to better understand these relationships,” noted researchers.
However, the associations were attenuated after further adjustment for change in lifestyle, which “suggest that the longitudinal protective effect of SAT on some individual components of MS might be partially attenuated by worsening lifestyles such as onset of smoking or alcohol or soft drink consumption,” they added.