Long-term probucol treatment results in regression of xanthomas, but in progression of coronary atherosclerosis in a heterozygous patient with familial hypercholesterolemia

Elevated lipid levels in patients with achilles tendon ruptures: a retrospective matching study

Background

Achilles tendon rupture (ATR) can lead to significant disability of patients. However, whether serum lipid levels are associated with ATR is still unclear. This study aimed to examine the difference in lipid levels between patients with and those without ATR.

Methods

Patients who received ATR surgery during January 2017 to December 2017 were categorized into the case group, and those who had physical examinations during the same period without ATR were in the control group. Different matching methods [case-control matching (CCM) and propensity score matching (PSM)] were used to match the cases and controls at a 1:1 ratio.

Results

Among a total of 216 pairs of subjects with CCM, cholesterol, triglyceride, and low-density lipoprotein (LDL) levels were significantly higher (all P<0.05) in the case group than in the control group. Among 241 pairs of subjects with PSM, the same results as those with CCM were obtained. Abnormal rates of cholesterol, triglyceride, and LDL levels in the case group were also significantly higher than those in the control group in CCM and PSM (all P<0.05). After adjusting for the factors of height and weight, there were still significant differences in cholesterol, triglyceride, and LDL levels, as well as high-density lipoprotein levels, between the case and control groups (all P<0.05).

Conclusions

Cholesterol, triglyceride, and LDL levels in patients with ATR are higher than those in healthy people. Further studies are required to verify the effect of some components of lipids on Achilles tendon structure.

Achilles tendon thickening is associated with disease severity and plaque vulnerability in patients with coronary artery disease

BACKGROUND

Tendon xanthomas are accumulations of collagen and macrophages, which contain cholesterol esters and a marker of high risk for coronary artery disease (CAD).

OBJECTIVE

The aim of the article was to clarify whether the presence of Achilles tendon thickening (ATT) was associated with disease severity and plaque vulnerability in patients with CAD.

METHODS

A total of 241 consecutive patients who underwent percutaneous coronary intervention and ATT assessment were analyzed. ATT was defined as Achilles tendon thickness of ≥9 mm on radiograph. The severity of CAD and plaque vulnerability was assessed by the findings on angiogram and optical coherence tomography, respectively.

RESULTS

ATT was found in 44 patients (18.2%). The frequency of multivessel disease (79.6% vs 58.4%, P = .009) and left main lesion (13.6% vs 3.1%, P = .004) was significantly higher in patients with ATT (ATT group) than in patients without ATT (no ATT group). Multivariate logistic regression analyses demonstrated that the presence of ATT was independently associated with the presence of multivessel disease (odds ratio, 2.33; 95% confidence interval, 1.08-5.46; P = .031). The ATT group had a higher prevalence of intimal vascular channels (50.0% vs 24.7%, P = .018) and macrophage accumulation (58.3% vs 33.3%, P = .028) in culprit plaque than the no ATT group.

CONCLUSIONS

Patients with the presence of ATT had a higher prevalence of multivessel coronary disease and left main coronary artery disease than with patients without ATT. The presence of ATT was also associated with vulnerable features, including intimal vascular channels and macrophage accumulation in culprit plaques.

Regression of Achilles Tendon Xanthomas Evaluated by CT Scan After Hypolipidemic Treatment with Simvastatin

Familial hypercholesterolemia (FH) is a relatively common autosomal monogenic disease with dominant inheritance and threefold to fourfold increase in relative risk of cardiovascular death in untreated patients. For a “definitive” clinical diagnosis of FH the Simon Broome Register proposes the presence of tendon xanthomas as a key feature. However, detection of tendon xanthomas by physical examination is subjective and difficult to use for follow-up purposes. Several instrumental methods have been reported to be more sensitive than physical examination for the evaluation of xanthomas. The present case illustrates the usefulness of computed tomography (CT) to detect xanthomas in the Achilles tendons (XAT) and their regression in response to hypolipidemic drug treatment in a heterozygous FH patient. As XAT are atherosclerotic plaque-like depositions of lipids it is likely that their progression or regression follows the behavior of vascular atherosclerotic lesions.

An exceptional case of xanthomatous infiltration of the musculoskeletal and integumentary systems

Tendinous and subcutaneous xanthomas are most commonly associated with primary hyperlipidemia. Xanthomatosis caused by cholesterol deposition can be a high risk marker for cardiovascular disease related to premature atherosclerosis; thus, early recognition of this diagnosis may reduce mortality and morbidity. Achilles tendon involvement is most common, followed by the extensor tendons of the hand and elbow. We present an exceptional case of tendinous and tuberous xanthomas, with intraoperative and histologic correlation, in a 34-year-old female manifesting with xanthomatous deposits of nearly all ankle tendons, plantar aponeurosis, extensor tendons of the hands, and various locations within the integumentum. To the authors' knowledge, only four studies to date have focused specifically on imaging findings of multifocal xanthomas. Thus, the radiographic and MR imaging descriptions of xanthomas in this report further add to the existing literature by helping to identify imaging characteristics of this multifocal systemic disease. The diagnosis of this condition should alert the physician to the presence of a dyslipidemia that can be treated with dietary modifications and/or drug therapy.

Pathogenesis, detection and treatment of Achilles tendon xanthomas

Tendon xanthomatosis often accompanies familial hypercholesterolaemia, but it can also occur in other pathologic states. Achilles tendons are the most common sites of tendon xanthomas. Low-density lipoprotein (LDL) derived from the circulation accumulates into tendons. The next steps leading to the formation of Achilles tendon xanthomas (ATX) are the transformation of LDL into oxidized LDL (oxLDL) and the active uptake of oxLDL by macrophages within the tendons. Although physical examination may reveal Achilles tendon xanthomas (ATX), there are several imaging methods for their detection. It is worth mentioning that ultrasonography is the method of choice in everyday clinical practice. Although several treatments for Achilles tendon xanthomas (ATX) have been proposed (LDL apheresis, statins, etc.), they target mostly in the treatment of the basic metabolic disorder of lipid metabolism, which is the main cause of these lesions. In this review we describe the formation, detection, differential diagnosis and treatment of ATX as well as the relationship between tendon xanthomas and atheroma.

Probucol Protects against Hypochlorite-induced Endothelial Dysfunction

Atherosclerosis is associated with endothelial dysfunction and a heightened state of inflammation characterized, in part, by an increase in vascular myeloperoxidase and proteins modified by its principal oxidant, hypochlorous acid (HOCl). Here we examined whether probucol could protect against endothelial dysfunction induced by the two-electron oxidant HOCl. Hypochlorous acid eliminated endothelium-dependent relaxation of rabbit aorta, whereas endothelial function and tissue cGMP was preserved and elevated, respectively, in animals pretreated with probucol. Exogenously added probucol also protected against HOCl-induced endothelial dysfunction. In vitro, HOCl oxidized probucol in a two-phase process with rate constants k(1) = 2.7 +/- 0.3 x 10(2) and k(2) = 0.7 +/- 0.2 x 10(2) m(-1) s(-1) that resulted in a dose- and time-dependent accumulation of probucol-derived disulfoxide, 4,4'-dithiobis(2,6-di-tert-butyl-phenol) (DTBP), DTBP-derived thiosulfonate, disulfone, and sulfonic acid, together with 3,3',5,5'-tetra-tert-butyl-4,4'-diphenoquinone (DPQ) as determined by high performance liquid chromatography and mass spectrometry. Like HOCl, selected one-electron oxidants converted probucol into DTBP and DPQ. Also, dietary and in vitro added DTBP protected aortic rings from HOCl-induced endothelial dysfunction and in vitro oxidation by HOCl gave rise to the thiosulfonate, disulfone, and sulfonic acid intermediates and DPQ. However, the product profiles of the in vitro oxidation systems were different from those in aortas of rabbits receiving dietary probucol or DTBP +/- HOCl treatment. Together, the results show that both probucol and DTBP react with HOCl and protect against HOCl-induced endothelial dysfunction, although direct scavenging of HOCl is unlikely to be responsible for the vascular protection by the two compounds.

Site-specific antiatherogenic effect of probucol in apolipoprotein E-deficient mice

-The lipid-lowering antioxidant probucol can inhibit atherosclerosis in animals and restenosis in humans. However, probucol has been shown to promote atherosclerosis in the aortic root of apolipoprotein E-deficient (apoE-/-) mice. In the current study, we examined the effects of probucol on both lesion formation at 4 sites along the aorta and lipoprotein oxidation in the plasma and aortas of apoE-/- mice receiving a diet containing 21.2% (wt/wt) fat and 0. 15% (wt/wt) cholesterol without or with 1% (wt/wt) probucol. After 6 months, controls had developed lesions at all sites investigated. Lesion development was strongly (P=0.0001) affected by probucol, but this effect was not uniform: lesion size was increased in the aortic root but significantly decreased in the arch, the descending thoracic aorta, and proximal abdominal aorta. Plasma and aortas of probucol-treated mice contained high concentrations of probucol and its metabolites (bisphenol and diphenoquinone); increased vitamin C; markedly decreased very low density lipoprotein (but not low density lipoprotein and high density lipoprotein); and decreased cholesterol, cholesteryl esters, triglycerides, vitamin E, and oxidized lipids compared with controls. Interestingly, probucol treatment did not decrease the proportion of aortic lipids that were oxidized. Plasma vitamin C and bisphenol, but not probucol, protected plasma lipids from ex vivo oxidation by peroxyl radicals. These results show that as in other species, probucol can inhibit lesion formation in most parts of the aorta of apoE-/- mice. This effect may involve lipid oxidation-independent mechanisms localized within the vessel wall as well as lipid lowering.

Dietary and pharmacological antioxidants in atherosclerosis

Antioxidants that inhibit LDL oxidation are thought to be potential anti-atherogenic compounds. The results of major human randomized trials with antioxidants have, however, been disappointing, except for probucol, which consistently inhibits restenosis. Similarly, animal intervention studies show that antioxidants do not generally inhibit atherosclerosis, although some compounds provide protection. Direct evidence for the oxidation of LDL causing atherosclerosis is needed. This article summarizes results from antioxidant intervention studies, and highlights some of the key issues that need to be addressed to link biochemical changes in the arterial wall more directly to the oxidation theory of atherosclerosis.

Current thinking in lipid lowering

In addition to elevated low-density lipoprotein (LDL) cholesterol, which has been conclusively proven to play a critical role in atherogenesis and coronary artery disease (CAD), other lipoprotein abnormalities are associated with CAD, such as reduced high-density lipoprotein (HDL) cholesterol; increased triglyceride-rich lipoproteins (very low density and intermediate-density lipoproteins); increased lipoprotein(a); small, dense LDL; and LDL with increased susceptibility to oxidation. Other, nonlipid factors such as homocysteine, fibrinogen, C-reactive protein, and soluble cell adhesion molecules may also have a role in risk stratification. The present US treatment guidelines, which focus on LDL cholesterol, stratify risk assessment and intensity of treatment by the presence of CAD; therefore, noninvasive imaging techniques such as ultrafast computed tomography and positron-emission tomography (PET) of the heart, which enable early detection of CAD, are useful in risk assessment. Because the influence of risk factors depends on their severity and combination, global risk assessment provides a necessary guide to the appropriate intensity of treatment. Agents are available that reduce LDL cholesterol and triglyceride and increase HDL cholesterol; although lipoprotein(a), LDL particle size, LDL oxidation, and homocysteine can also be altered, the clinical effects of such alterations are not known. Combination therapy that simultaneously improves multiple components of the lipid profile may provide additional benefit compared with monotherapy. To provide cost-effective treatment to the most patients, high-risk patients must be identified through systematic screening. Then each patient should be treated with the most cost-effective agent(s) that will enable achievement of the lipid levels recommended in the guidelines.