Cardiovascular Consequences of Weight Gain

SOURCE: Bangalore S, et al. N Engl J Med 2017;376:1332-1340.

Obesity is recognized as an independent risk factor for numerous health consequences, including hypertension, cardiovascular events, cancer, and osteoarthritis. Whether progressive weight gain is associated with adverse outcome might be intuitively obvious, but has been less studied. The object of this report by Bangalore et al was to examine the association between weight variability and health outcomes, specifically addressing coronary heart disease.

The Treating to New Targets trial randomized patients with known coronary artery disease (n = 10,001) and a low-density lipoprotein reading of < 130 mg/dL to low-dose atorvastatin (10 mg/day) vs. high-dose (80 mg/day). In this post-hoc analysis, the authors examined the relationship between weight variability and subsequent coronary heart disease events over a mean five years’ treatment.

For every 1.5-1.9 kg increase in body weight from baseline, the risk of incurring a coronary event increased by 4%. The increase in body weight in persons who were normal weight at enrollment was associated with a numerically greater (but not statistically significant) number of coronary events. However, persons who were overweight or obese exhibited marked increases in coronary events proportional to the degree of their weight gain. Clinicians should be vigilant to offer patients with coronary disease advice about optimal weight management.

Efficacy of Mandibular Advancement Devices vs. CPAP

SOURCE: Kuhn E, et al. Chest 2017;151:786-794.

Although there are “organic” rewards for the treatment of obstructive sleep apnea (OSA), such as blood pressure reduction in hypertensives, much of the benefit of intervention resides in the quality of life (QOL) category: less daytime fatigue, better concentration, less snoring, etc. Despite such favorable effects, short- and long-term compliance with continuous positive airway pressure (CPAP) often is difficult. How does the efficacy of mandibular advancement devices (MANDs) for QOL compare?

Kuhn et al performed a network metaanalysis of clinical trials (n = 23) that compared CPAP and/or MANDs to inactive control. The outcome of interest was QOL as assessed by the mental and physical components of the SF-36 score. Both CPAP and MANDs resulted in improved physical and mental segments of the SF-36 score, and there was no statistically significant difference between the two methods in efficacy.

MANDs often have been prescribed for patients with less severe OSA (mild-moderate), for patients who could not tolerate CPAP, or for persons for whom CPAP was not effective. These results suggest that MANDs are a viable alternative. The authors recommended that CPAP should remain the first-line treatment for most patients, perhaps because the studies employing MANDs have been restricted to less severe OSA cases.

Exercise-induced Rhabdomyolysis

SOURCE: Brogan M, et al. Am J Med 2017;130:484-487.

For exceptionally young clinicians who are unfamiliar with Mae West (1893-1980), she was an actress, playwright, comedian, and screenwriter credited with quotes such as, “When choosing between two evils, I always like to try the one I’ve never tried before,” and, “Too much of a good thing is a really good thing.” However, there are exceptions to all rules, right?

Sometimes, a segment of the population that decides to embrace exercise does too much of a good thing. Brogan et al enlightened us about 46 reported cases of acute rhabdomyolysis that occurred specifically after engaging in the vigorous activity of spinning: the use of stationary cycles that are adjustable for the degree of resistance and steepness of climb.

Even among physically fit women, a substantial amount of time above the ventilatory threshold (the level at which lactate begins to accumulate) is spent during a 45-minute spin class. Of the 46 above-mentioned cases of spin-class related rhabdomyolysis, 42 occurred after the first spinning class (in presumably less-conditioned individuals).

While clinicians endorse the health benefits of engaging in physical activity, patients who decide to choose spinning (cycling) as their exercise method must be cautioned to build exercise intensity gradually rather than doing too much of a good thing.