Does bariatric surgery cure the metabolic syndrome?

Metabolic syndrome (MS) is a risk condition for the development of systemic atherosclerotic disease. Morbid obesity is a state of insulin resistance (IR) associated with visceral fat accumulation, which is involved in the development of MS. In severe obesity, conservative therapies promote an improvement of MS, but weight regain is frequent, whereas bariatric surgery promotes a more significant and sustained weight loss. Bariatric surgery is recommended for patients with unsatisfactory response to clinical treatment and with IMC > 40 kg/m(2) or > 35 in case of co-morbidities. In those cases, surgical risk must be acceptable and patients submitted to surgery must be informed about complications and postoperative care. Prevention, improvement and reversion of diabetes (DM2) (70 to 90% of cases) are seen in several bariatric surgery modalities. Disabsorptive are more efficient than restrictive procedures in terms of weight reduction and insulin sensitivity improvement, but chronic complications, such as malnutrition, are also more frequent. Vertical gastroplasty with jejunoileal derivation is a mixed surgery in which the restrictive component predominates. In this modality, reversion of DM2 is due to an increase in insulin sensitivity associated with improved beta cell function. Reversion of MS and its manifestations after bariatric surgery are associated with reduction of cardiovascular mortality and, thus, in severe obesity cases, MS can be considered a surgical condition.     

Does the metabolic syndrome predict mobility impairment in the elderly?

The predictive importance of the metabolic syndrome and its components for declining mobility were tested in a 5-year follow-up study of four elderly birth cohorts (65, 75, 80 and 85 years of age; n=946). In the age group of 65 years, the subjects with mobility decline were more often diabetics (24.6 vs. 15.5%, P=0.060), had higher blood glucose (6.2 vs. 5.8 mmol/l, P<0.05), higher fasting plasma insulin (13.2 vs. 11.4 IU/l, P<0.01), and higher body mass index (28.4 vs. 27.2 kg/m(2), P<0.05) than the others. In the 75 year-old group, the mobility decline was associated with lower HDL-cholesterol (1.4 vs. 1.6 mmol/l, P<0.05) and higher insulin (15.9 vs. 12.8 IU/l, P<0.10). In the 80 year-old group, insulin was higher in subjects whose mobility declined (11.3 vs. 17.9 IU/l, P<0.05) but in the oldest group insulin tended to be lower in the subjects with declining mobility. In non-diabetic subjects, blood glucose and plasma insulin were associated with declining mobility in the 65 year-old cohort, only. After controlling for gender and baseline mobility, one quartile of both insulin and BMI increased the probability of mobility decline by 35%, mainly of difficulties in walking up stairs. Of the components of metabolic syndrome, obesity and hyperinsulinemia as its consequence appear causal of declining mobility.     

Does the metabolic syndrome add to the diagnosis and treatment of cardiovascular disease?

Much controversy has surrounded both the pathological basis and the clinical utility of the metabolic syndrome. Key questions still revolve around the definition of this syndrome, its utility as a predictor of cardiovascular risk, and the treatment implications of diagnosis. The metabolic syndrome is associated with increased cardiovascular risk. However, the metabolic syndrome clearly underperforms compared with other, established prediction equations, such as the Framingham Risk Score and SCORE (Systemic COronary Risk Evaluation). Differences arise because the components are highly correlated (whereas other tools specifically include independent predictors) and because diagnosis is based on dichotomized variables. These facts, together with uncertain pathophysiology, mean that the metabolic syndrome in its current manifestation has limited utility for the diagnosis and treatment of cardiovascular disease. The syndrome has, however, served and continues to serve a useful purpose in raising awareness of the metabolic consequences of obesity, and as a spur for research into metabolic risk factor interactions.     

Which features of the metabolic syndrome predict the prevalence and clinical outcomes of angiographic coronary artery disease?

BACKGROUND: The prevalence of the metabolic syndrome (MS) is growing. The Adult Treatment Panel (ATP) III provided a uniform definition of MS but no information on its predictive ability. METHODS: We tested the ability of MS and its components to predict angiographic coronary artery disease (CAD) and incident death/myocardial infarction (D/MI) over 2.8 +/- 2.3 years in a large cohort of patients undergoing angiography. ATP-III criteria were used for fasting glucose (FG), triglyceride (TG), high-density lipoprotein cholesterol (HDL), and blood pressure (BP); body mass index (BMI) >27 kg/m(2) was used as a surrogate for waist circumference. RESULTS: 3,128 subjects were studied; 65% had advanced CAD (>/=70% stenosis), and 35%, no CAD. MS was present in 64% (high FG 40%; high TG 52%; low HDL 71%; high BP 76%; high BMI 58%). Presence of CAD was predicted by MS [adjusted odds ratio (OR) = 1.30, 95% CI 1.10-1.55, p = 0.003] and, individually, by high FG (OR = 1.90, CI 1.63-2.23) and low HDL (OR = 1.38, CI 1.18-1.62). In multivariable modeling, CAD was predicted by high FG (OR = 1.80, CI 1.51-2.16) and low HDL (OR = 1.57, CI 1.31-1.89) as well as by age, gender, family history, smoking, and LDL cholesterol (all p < 0.001). For secondary risk of incident D/MI, only high FG of MS features was predictive (adjusted hazard ratio 1.46, CI 1.17-1.82, p = 0.001), and this risk was carried by diabetes (adjusted hazard ratio 1.71, p < 0.001); other predictors were age, heart failure, revascularization strategy, renal insufficiency, prior MI, and number of diseased vessels. CONCLUSION: MS has primary predictive ability for CAD, carried primarily by high FG and low HDL. Secondary predictive ability of MS features for clinical outcomes, in the setting of established CAD, is carried by diabetes alone. Dysglycemia deserves specific attention as a target for prevention and treatment.     

Does using ethnic specific criteria improve the usefulness of the term metabolic syndrome? Controversies and suggestions

The metabolic syndrome (MetS) is an important tool that identifies populations at increased risk for cardiovascular disease (CVD) and type 2 diabetes, targeting them for preventive measures. The criteria for the identification of the MetS were initially constructed from data in Caucasian populations. Recent research suggests that the current criteria for the MetS may not accurately characterize disease risk in non-Caucasian populations, either over or underestimating the risk in certain ethnic groups. Altering the criteria for each population by making ethnic-specific cutoffs as has been done with waist circumference will help in more accurate characterization. Using different combinations of the MetS criteria for different ethnic groups based CVD risk and factor analysis needs consideration. With better characterizations of patient populations, the ultimate goal would be to make MetS more accurate for predicting CVD risk while retaining the ease of screening afforded by the MetS. The proposed alterations of definition and criteria of the MetS would ensure its continued viability and sustainability.     

Does claudication affect the development of coronary collaterals?

Atherothrombosis is a generalized disease process that affects large- and medium-diameter arteries throughout the arterial tree. In this study, we aimed to evaluate the correlation between collaterals in different vascular beds. Patients who had undergone digital subtraction angiography for symptomatic lower extremity peripheral arterial disease and coronary angiography after an acute anterior myocardial infarction (MI) were compared with a control group composed of those patients who were hospitalized for acute anterior MI and underwent coronary angiography but had no claudication and had an ankle-brachial index of greater than 0.9 in both legs. In claudicants, stenosis in the left anterior descending artery (LAD) (90.3 ± 17.5 vs 78.6 ± 13.8, P = 0.005) was greater compared with the patients without claudication. The collaterals to the LAD (88% vs 37.5%, P = 0.001) and the collateral grades (1.7 ± 0.7 vs 0.7 ± 0.9, P = 0.001) were higher in the patients with claudication compared with those without claudication. A previous history of angina (52.2% vs 16.3%, P = 0.001), claudication (39.1% vs 4.6%, P = 0.001), and peripheral collaterals (45.7% vs 6.9%, P = 0.001) were higher in the patients with coronary collaterals than in those without. The factors affecting the development of coronary collaterals were claudication [relative risk (RR): 8.8; 95% confidence interval (CI): 2.1–39.8], peripheral collaterals (RR: 1.1; 95% CI: 1.1–1.3), and LAD stenosis (RR: 1.2; 95% CI: 0.03–29.1). Our results suggest that the presence of collateralization or angiogenesis in one vascular bed highly predicts collateralization in another arterial bed.     

Does gender influence the patency of infrainguinal bypass grafts?

Infrainguinal revascularization is an effective method of treatment for femoropopliteal/tibial occlusive diseases. However, these bypass grafts are prone to stenosis. In this retrospective study, the authors investigate the association of gender with patency of infrainguinal bypass grafts. The outcomes for consecutive 375 male and 200 female patients who underwent infrainguinal bypass surgery for arterial occlusive disease are compared, and associations with characteristics of the patients, surgical procedure, and graft stenosis are determined. It is found that several demographic, biochemical, and etiological factors could influence the patency of bypass procedures in different genders. However, infrainguinal arterial reconstruction procedures performed in women have a worse outcome when compared with that in men.     

Adrenal incidentaloma: a new cause of the metabolic syndrome?

A number of patients with adrenal incidentaloma are exposed to a slight degree of cortisol excess resulting from functional autonomy of the adrenal mass (usually a cortical adenoma). At present, there are only scant data on the unwanted effects of this endocrine condition referred to as subclinical Cushing's syndrome. The aim of the present study was to look for some features of the metabolic syndrome in patients with incidental adrenal adenoma. Forty-one patients (9 men and 32 women) bearing adrenal incidentaloma with typical computed tomography features of cortical adenoma were studied. For both patients and controls, exclusion criteria were age equal to 70 yr or greater, previous history of fasting hyperglycemia, or impaired glucose tolerance (IGT), severe hypertension, current use of medication or concomitant relevant illnesses, and body mass index (BMI) equal to 30 kg/m(2) or greater. Forty-one patients with euthyroid multinodular goiter accurately matched for sex, age, and BMI served for a 1:1 case-control analysis. The study design included an oral glucose tolerance test (75 g) and an endocrine workup aimed at the study of the hypothalamic-pituitary-adrenal axis. Age and BMI were fully comparable between patients (54.0 +/- 10.7 yr, 23.8 +/- 2.4 kg/m(2)) and controls (52.2 +/- 11.6 yr, 23.5 +/- 2.8 kg/m(2)). Fasting glucose and fasting insulin levels were not different between the two groups (4.96 +/- 0.61 mmol/liter vs. 4.88 +/- 0.58 mmol/liter; 67 +/- 34 pmol/liter vs. 59 +/- 32 pmol/liter), but the 2-h postchallenge glucose was significantly higher in patients than in controls (7.43 +/- 2.49 mmol/liter vs. 6.10 plus minus 1.44 mmol/liter, P = 0.01). Fifteen patients (36%) reached the World Health Organization criteria for IGT and two other patients (5%) reached those for diabetes, and 14% of the controls qualified for IGT (P = 0.01). No difference in the lipid pattern was seen between the two groups, but either systolic or diastolic blood pressure were higher in patients (135.4 +/- 15.5 mm Hg vs. 125.0 +/- 15.6 mm Hg, P = 0.003; 82.9 +/- 9.1 mm Hg vs. 75.3 +/- 6.6 mm Hg, P < 0.0001). We calculated the whole-body insulin sensitivity index derived from the oral glucose tolerance test that was significantly reduced in the patients (4.3 +/- 1.7 vs. 5.7 +/- 2.5, P = 0.01). In a multiple regression analysis, 2-h glucose was associated with BMI and midnight cortisol values (r(2) = 0.36, P = 0.002). The comparison of the patients with nonfunctioning adenoma (n = 29) with those with subclinical Cushing's syndrome (n = 12) yielded significant differences as to 2-h glucose and triglyceride levels, which were significantly higher in the second group (7.02 +/- 1.76 mmol/liter vs. 8.72 +/- 3.17 mmol/liter, P = 0.03; 1.06 +/- 0.4 mmol/liter vs. 1.73 +/- 0.96 mmol/liter, P = 0.002), but the insulin sensitivity index was conversely reduced (5.2 +/- 1.4 vs. 2.9 +/- 1.2, P < 0.0001). In conclusion, many patients with incidental adrenal adenoma display altered glucose tolerance, that may be explained by reduced insulin sensitivity, and increased blood pressure levels in comparison with carefully age- and BMI-matched controls. The slight hypercortisolism observed in some such patients may significantly contribute to this state of insulin resistance. Midnight serum cortisol appears as a sensitive marker of the metabolic effects of subclinical Cushing's syndrome.