Obesity in the elderly: More complicated than you think

Lifestyle interventions: Diet and exercise

The goal is to induce an energy deficit by reducing energy intake, increasing energy expenditure, or both—by 500 to 1,000 calories a day. This generally leads to a loss of 1 to 2 lb per week, and possibly up to 10% of weight in 6 months. Loss of about 10 to 20 lb with diet and exercise can translate to a relatively large reduction in visceral fat, with subsequent improvement in metabolic abnormalities.

A regular exercise program is important for improving overall physical function, which can slow progression to frailty. Adding aerobic, endurance, and resistance training helps preserve fat-free mass, which otherwise tends to diminish during active weight loss.^55–57

The exercise program should begin at the outset of the weight-loss effort to help maintain weight loss and to prevent weight regain.⁵⁸ Exercise is not essential for reaching the targeted weight loss, but starting early is important to reduce the loss of lean muscle that is usually already seen in the older population.

Several studies indicate that diet and exercise are just as effective in middle-aged and older people (over age 60) as in the younger population.^58–60 Older people in the Diabetes Prevention Program were more compliant with lifestyle interventions and lost more weight than younger participants⁴⁹: 60% of the older group met the 7% weight-loss goal at the end of 24 weeks, compared with 43% of those under age 45. At 3 years, the numbers were 63% vs 27%.

In a small randomized controlled trial,⁶¹ fat mass decreased by 6.6 kg in 17 people assigned to a program of diet and exercise, compared with a gain of 1.7 kg in a control group of 10 patients. Fat-free mass decreased by about 1 kg in both groups. The authors concluded that diet plus exercise (resistance training and strength training in this trial) could ameliorate frailty in obese older adults.

If exercise is appropriate, a physician should write a prescription for it, especially for resistance training, strengthening, flexibility, and stretching. This is important for patients with sarcopenic obesity and for those at high risk of chronic bone loss. The 2007 American College of Sports Medicine guidelines recommend muscle-strengthening activity of 8 to 10 exercises involving the major muscle groups, 10 to 15 repetitions at least twice a week. Flexibility and balance exercises should be included for those at risk of falls.⁶²

Pharmacotherapy

At present, there are two general classes of weight-loss drugs: appetite suppressants and drugs that interfere with nutrient absorption.

Appetite suppressants include the sympathomimetics, which stimulate the release of dopamine and norepinephrine, resulting in increased satiety. Data—and therefore, recommendations—on their use in the elderly are very scarce, as most randomized controlled trials included only a small number of older people. A meta-analysis of drug therapy to treat obesity noted that the study population ranged in age from 34 to 54.⁶³

The only approved drug currently available for use in older adults is orlistat, which blocks absorption of dietary fat by binding to intestinal lipase. A randomized controlled trial found the weight loss with orlistat to be comparable in older and younger adults.^64,65

Review medications than can cause weight gain

When assessing older adults, always review the drugs they are taking. Those known to cause weight gain include certain of the following:

• Antiepileptics (eg, gabapentin)
• Antipsychotics (eg, olanzapine)
• Antidepressants (eg, tricyclics)
• Antihyperglycemic drugs (eg, sulfonylureas, thiazolidinediones)
• Beta-blockers
• Steroids.

If medically appropriate, a weight-neutral drug should be substituted for one suspected of causing weight gain. If a different physician (eg, a specialist) prescribed the original drug, he or she should be notified or consulted about any change.

Bariatric surgery

Bariatric surgery is the most effective weight-loss option, and more older patients are undergoing it than in the past. Dorman et al⁶⁶ showed that the number of patients age 65 or older undergoing bariatric surgery increased from the year 2005 (when they accounted for 2%) to 2009 (when they accounted for 4.8%).

However, very few studies have provided information on the safety and effectiveness of bariatric surgery in older people. Several reports concluded that rates of perioperative morbidity and mortality are higher in older patients.^67–69 Surgery resulted in marked weight loss and improvement in obesity-related complications and physical disability in older patients, although by a lower rate than in younger patients.

Varela et al⁷⁰ examined the outcomes of bariatric surgery in a database from the University Health System Consortium Centers between 1999 and 2005. Patients over age 60 accounted for 1,339 (2.7%) of all bariatric operations performed. Compared with young and middle-aged patients, older patients had more comorbidities, longer hospital stays, and more complications, in addition to a higher in-hospital mortality rate. When risk-adjusted, the observed-to-expected mortality ratio for the older group was 0.9, compared with 0.7 in the young and middle-aged cohort.

Willkomm et al⁷¹ found an apparently higher operative risk profile in those over age 65 (n = 100) than in younger patients (n = 1,374), with higher rates of sleep apnea, diabetes, and hypertension. However, the operative outcomes were similar in the two groups in terms of operative time, length of stay, and 30-day readmission rates. The authors concluded that patients over age 65 had excellent outcomes compared with younger patients, suggesting that older age is not a risk factor for complications or death with bariatric surgery.

The American College of Surgeons National Surgical Quality Improvement Program evaluated the outcomes of 48,378 adults with a BMI greater than or equal to 35 kg/m² who underwent bariatric surgery between 2005 and 2009.⁶⁶ During this time, the number of patients age 65 and older seeking bariatric surgery increased from 1.5% to 4%. A total of 1,449 patients were in this age range. Thirty-day mortality rates did not differ significantly by age group and were less than 1% for all age ranges. Being age 65 or older was a significant predictor of prolonged length of stay but not of major adverse events. Significant predictors of major adverse events were a BMI greater than or equal to 55 kg/m², cardiac comorbidities, a severe American Society of Anesthesiologists score, albumin levels lower than 3 g/dL, and creatinine levels greater than 1.5 mg/dL.

The most up-to-date study of the outcomes of bariatric surgery in patients over age 70 was a retrospective review at a single institution from 2007 to 2008 of 42 patients who underwent bariatric surgery.⁷² Twenty-two patients had laparoscopic gastric banding, 12 had laparoscopic sleeve gastrectomy, and 8 underwent laparoscopic Roux-en-Y gastric bypass. No patient died, complications occurred in 9 patients, and the rates of postoperative use of medications for hypertension, hyperlipidemia, diabetes, and osteoarthritis were reduced by about half. With the increasing number of patients seeking bariatric surgery, especially those over age 70, further prospective studies will determine if the outcomes are statistically significant.

If bariatric surgery is considered

The outcomes, complications, and mortality rates associated with bariatric surgery have been shown to be acceptable for adults age 65 and older. Perioperative risk assessment in the older obese patient seeking bariatric surgery is paramount to ensure that the benefits of the procedure justify any associated risks to the patient. Consequently, patients over age 65 should not be excluded out of hand: the patient’s individual risk of major adverse events must be identified beforehand.

If the patient is at risk, efforts should be made to reduce the risk to an acceptable level, including cardiac risk stratification, optimization of drug therapy, and discussions with the bariatric surgeon to plan on a less-invasive laparoscopic procedure. Otherwise, older obese patients can safely proceed with conventional bariatric surgery, which will help them achieve durable weight loss, improve quality of life, and reduce associated comorbidities.

The aforementioned studies of bariatric surgery are retrospective, include small numbers of patients, and lack long-term follow-up. The issues of long-term safety and the risk of death and morbidity in the aging population will require randomized controlled trials to answer these important questions.

At our hospital, we have seen an increase in the number of patients referred for a possible additional procedure (revision) to correct a problem from a previous bariatric surgery. The problems arising from the previous surgery can lead to weight gain or to excessive weight loss and malnutrition. To date, our institution has no policy on when to consider a revisional procedure in an older patient. All patients, including older ones, are assessed for the procedure on a case-by-case basis.