Metabolic syndrome is not linked to a significant increase in carotid plaque destabilization, but rather with the presence of stable plaques, according to findings published in Cardiovascular Diabetology. It was noted, however, that female patients with hypertriglyceridemia and metabolic syndrome appear to have increased unstable carotid plaques. Researchers indicated that controlling hypertriglyceridemia should be a key step in preventing carotid atherosclerotic plaque destabilization, particularly in postmenopausal female patients.
Researchers have shown that metabolic syndrome (MetS), which is defined as a cluster of interconnected metabolic risk factors (including abdominal obesity, hypertriglyceridemia, hypertension, elevated fasting glucose, and low high-density lipoprotein [HDL] cholesterol levels), increases the risk for atherosclerosis and cardiovascular disease, and recent researchers have focused on how insulin resistance may play a role in this risk. Although it is true MetS encourages the growth of carotid plaque, investigators indicated that it is uncertain if it leads to plaque destabilization, or if only certain components of the syndrome are linked to increased risk for plaque destabilization. Investigators planned this study to assess the effect of the various elements of MetS, both as a syndrome and individually, on carotid plaque destabilization.
A total of 186 carotid plaques from asymptomatic and symptomatic patients who were received surgical carotid endarterectomies (CEA) at the University of Tor Vergata in Rome, Italy, from 2016 to the present were retrospectively and histologically analyzed, and then correlated with major cardiovascular risk factors. Symptomatic was defined as affected by ipsilateral major stroke or transient ischemic attack.
The mean patient age at time of CEA was 72.6 ± 8.6 years, 70.4 % (n=131 of 186) were men, and 29.6 % (n=55 of 186) were women. Of the total 186 patients, 74 (39.8 %) were symptomatic, and 112 (60.2 %) were asymptomatic.
Eighty-five of the 186 patients (45.7%) had MetS, and all patients had at least one risk factor, with hypertension being the most common (162 patients; 87.1% according to ACC/AHA criteria and 112 patients, 60.2% according to ESC/ESH criteria). Unstable plaques were found in 82 out of 186 patients (44.1%), and the remaining 104 carotids (55.9 %) showed a stable plaque. A large calcification was observed in 33 plaques, some unstable and some stable.
Unstable plaque incidence in patients with MetS is only 43.9%; however, that low incidence significantly increases among female patients with hypertriglyceridemia, with an odds ratio (OR) of 3.01 (95% CI, 0.25-36.30). The uni- and multivariate analysis showed no correlation between unstable carotid plaque presence and specific risk factors, or the use of antihypertensive drugs or statins. Only sex showed a significant correlation, with men showing a higher incidence of unstable plaques than women (n=66 of 131, 50.45%; vs n=16 of the 55, 29.1%; P =.01).
The overall incidence of unstable plaques in patients with MetS was low (n=36 of 85, 42.4%), with no significant differences compared with stable plaques (P =.77). The greatest OR for unstable plaque was seen for patients with hypertriglyceridemia (OR, 1.80; 95% CI, 0.93-3.63) or hypertension (OR, 1.47; 95% CI, 0.57-3.84). When multivariate analysis was used to consider MetS for plaque instability (instead of abdominal obesity, diabetes, hypertension, hypertriglyceridemia, and low HDL-C), a low OR was found (OR, 0.91; 95% CI, 0.49-1.71).
Patients with hypertriglyceridemia showed the greatest risk for plaque destabilization (OR, 1.56; 95% CI, 0.50-4.89), and as a significant inverse correlation was observed between age and triglyceridemia (r=-0.44; P =.001), investigators calculated the risk in patients ±70 years old with MetS. Patients <70 had an OR of 1.55 (95% CI; 0.25-9.54), while the risk reduced to 1.00 (95% CI, 0.17-5.76) in those over 70. Women showed a significant increase in risk, with an OR of 3.01 (95% CI, 0.25-36.30) compared with an OR of 1.28 (95% CI, 0.37-4.48) among men.
No significant increase was observed in other combinations of MetS components.
Investigators indicated that the “results support the hypothesis that the control of hypertriglyceridemia should be a key point on prevention of the destabilization of atherosclerotic carotid plaque, especially in postmenopausal female patients”.
Servadei F, Anemona L, Cardellini M, et al. The risk of carotid plaque instability in patients with metabolic syndrome is higher in women with hypertriglyceridemia [published online May 6, 2021]. Cardiovasc Diabetol. doi: 10.1186/s12933-021-01277-8