Impact of weight-loss medications on the cardiovascular system: focus on current and future anti-obesity drugs

Clinical Impact of Weight-Loss Pharmacotherapy in Patients with Atherosclerotic Cardiovascular Disease

Obesity is associated with the development and progression of multiple cardiovascular risk factors, such as hypertension, dyslipidemia, and type 2 diabetes mellitus, and is an important contributor to the global burden of atherosclerotic cardiovascular disease (CVD). Guidelines suggest that clinicians provide lifestyle counseling and promote lifestyle modifications before considering weight-loss surgery. However, despite lifestyle modifications and increased physical activity, most patients with obesity will not lose significant weight or will experience weight regain. Weight-loss pharmacotherapy added to lifestyle modification has long been perceived as a bridge between lifestyle modifications alone and weight-loss surgery. However, since its inception, weight-loss pharmacotherapy has been plagued by variable efficacy and concern about cardiovascular safety. Following requirements from regulatory authorities, efficacy and cardiovascular safety trials have been conducted for the currently available weight-loss pharmacotherapeutic agents. Overall, these trials have shown that weight-loss pharmacotherapy is only modestly efficient for the inducement of weight loss. Recent trials have also demonstrated the cardiovascular safety of some of these agents. We review these trials with a focus on the clinical impact of these weight-loss pharmacotherapeutic agents in patients with atherosclerotic CVD.

New medications for treatment of obesity: metabolic and cardiovascular effects

The management of obesity remains a major challenge. Dietary therapy often fails, whereas bariatric surgery, although successful, is demanding and applicable to a limited number of patients. Drug therapy has had many setbacks over the past 20 years because of serious adverse effects; however, several new drugs for the treatment of obesity are either licensed in some parts of the world, submitted for registration, or completing phase III trials. These include combinations (at low dose) of existing drugs, e.g., bupropion + naltrexone (Contrave), phentermine + topiramate (Qsymia), higher doses of existing drugs licensed for other indications (liraglutide, 3 mg), and new entities (lorcaserin). We discuss the challenges and opportunities for obesity pharmacotherapy and review in detail the efficacy of the new drugs regarding weight loss and both desirable and potential undesirable cardiovascular (CV) and metabolic risk factors. Substantial barriers remain, even if the drugs are approved, in successfully integrating these agents into weight management practice, largely related to cost, patient acceptability, and clinician willingness to be engaged in obesity treatment. Although hard clinical outcome benefit (at least for CV outcomes) has yet to be established, obesity pharmacotherapy may soon address many of the challenges in the clinical management of obesity, although newer and better drug combinations and more evidence of benefit from appropriately designed outcome trials is needed.

Improvement in insulin sensitivity following a 1-year lifestyle intervention program in viscerally obese men: contribution of abdominal adiposity

The objectives of the study were to quantify the effect of a 1-year healthy eating-physical activity/exercise lifestyle modification program on insulin sensitivity in viscerally obese men classified according to their glucose tolerance status and to evaluate the respective contributions of changes in body fat distribution vs changes in cardiorespiratory fitness (CRF) to the improvements in indices of plasma glucose/insulin homeostasis. Abdominally obese, dyslipidemic men (waist circumference ≥90 cm, triglycerides ≥1.69 mmol/L, and/or high-density lipoprotein cholesterol <1.03 mmol/L) were recruited. The 1-year intervention/evaluation was completed by 104 men. Body weight, composition, and fat distribution were assessed by dual-energy x-ray absorptiometry/computed tomography. Cardiorespiratory fitness and cardiometabolic risk profile were measured. After 1 year, insulin sensitivity improved in association with decreases in both visceral (VAT) and subcutaneous adiposity (SAT) as well as with the improvement in CRF, regardless of baseline glucose tolerance. Further analyses were performed according to changes in glucose tolerance status: improvement (group I, n = 39), no change (group N, n = 50), or worsening (group W, n = 15) after 1 year. Groups I and N improved their insulin sensitivity and their CRF, whereas group W did not, while losing less VAT than groups I and N. Multiple regressions showed that reduction in VAT was associated with an improvement in homeostasis model assessment of insulin resistance, whereas reduction in SAT was rather associated with improvement of the insulin sensitivity index of Matsuda. Changes in CRF were not independently associated with changes in indices of plasma glucose/insulin homeostasis. A 1-year lifestyle intervention improved plasma glucose/insulin homeostasis in viscerally obese men, including those with normal glucose tolerance status at baseline. Changes in SAT and VAT but not in CRF appeared to mediate these improvements.

Coronary heart disease and body fat distribution

Larger waist circumference or waist-hip ratio, as crude indicators of visceral fat mass, are associated with adverse metabolic profile, but their role in predicting future coronary heart disease (CHD) events has been less investigated. Recent epidemiologic findings suggest that these simple and inexpensive measures of abdominal fat distribution predict CHD independently of body mass index, and, to a certain extent, cardiovascular disease risk factors. The magnitude and shape of the association between abdominal adiposity and CHD have been shown to vary with age, gender, and ethnicity. Studies have also suggested that lower body fat is associated with reduced CHD risk, although the clinical relevance for this finding needs further elucidation. Assessing body fat distribution may be useful for improving CHD risk assessment, although more studies are needed to assess consistency in CHD risk predictions across populations. A consensus is also needed to define the clinically relevant cut-off points for waist circumference or waist-hip ratio.

Cardiovascular Evaluation and Management of Severely Obese Patients Undergoing Surgery

Obesity is associated with comorbidities that may lead to disability and death. During the past 20 years, the number of individuals with a body mass index >30, 40, and 50 kg/m 2 , respectively, has doubled, quadrupled, and quintupled in the United States. The risk of developing comorbid conditions rises with increasing body mass index. Possible cardiac symptoms such as exertional dyspnea and lower-extremity edema occur commonly and are nonspecific in obesity. The physical examination and electrocardiogram often underestimate cardiac dysfunction in obese patients. The risk of an adverse perioperative cardiac event in obese patients is related to the nature and severity of their underlying heart disease, associated comorbidities, and the type of surgery. Severe obesity has not been associated with increased mortality in patients undergoing cardiac surgery but has been associated with an increased length of hospital stay and with a greater likelihood of renal failure and prolonged assisted ventilation. Comorbidities that influence the preoperative cardiac risk assessment of severely obese patients include the presence of atherosclerotic cardiovascular disease, heart failure, systemic hypertension, pulmonary hypertension related to sleep apnea and hypoventilation, cardiac arrhythmias (primarily atrial fibrillation), and deep vein thrombosis. When preoperatively evaluating risk for surgery, the clinician should consider age, gender, cardiorespiratory fitness, electrolyte disorders, and heart failure as independent predictors for surgical morbidity and mortality. An obesity surgery mortality score for gastric bypass has also been proposed. Given the high prevalence of severely obese patients, this scientific advisory was developed to provide cardiologists, surgeons, anesthesiologists, and other healthcare professionals with recommendations for the preoperative cardiovascular evaluation, intraoperative and perioperative management, and postoperative cardiovascular care of this increasingly prevalent patient population.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.