25% of adults with SMA in German study had metabolic syndrome
Those with syndrome noted worse quality of life, more fatigue
Many adults with spinal muscular atrophy (SMA) have metabolic syndrome, and those who do tend to report worse life quality and fatigue, according to a study from Germany.
Nine of 36 SMA adults enrolled in the study — exactly one-quarter — met the diagnostic criteria for metabolic syndrome, or MetS, according to the study, “Metabolic syndrome is common in adults with 5q-spinal muscular atrophy and impacts quality of life and fatigue,” published in Muscle and Nerve.
MetS refers to a cluster of conditions that are known to increase the risk for diabetes and heart disease, including obesity, high blood pressure, and abnormal levels of fats, sugars, and cholesterol in the blood.
The prevalence of MetS varies substantially from place to place, influenced heavily by lifestyle and cultural norms. In Japan, only about one in 20 people in the general population has MetS, whereas in the U.S., the figure is closer to one in four. In Germany, it’s estimated that approximately one in five (19.8%) people in the general population has MetS.
Some research has suggested that people with neuromuscular disorders like SMA might be more likely to develop MetS, largely because people with these disorders are usually less mobile than those without, so they typically don’t burn as many calories in their day-to-day lives. But there hasn’t been much investigation into the prevalence of MetS in adults with SMA.
Understanding MetS in light of new SMA treatments
The team noted that understanding the impact of MetS on people with SMA is especially important now that there are multiple treatments to address the underlying cause of the disease, helping slow disease progression and allowing patients to live longer with more functionality. The fact that people with SMA are expected to live longer “may increase susceptibility to age-related conditions such as diabetes mellitus, hypertension and subsequently, MetS,” the researchers said.
The 25% figure for MetS is just slightly higher than estimates for the general population of Germany. The researchers noted that given the study’s small sample size, it isn’t clear whether this is a meaningful difference.
Most individuals with SMA and MetS were non-ambulatory, and over half of them were classified as obese. Central obesity was the most prevalent component of MetS, affecting nearly 70% of individuals. Almost half of the SMA patients exhibited at least one abnormal lipid level in their blood.
Among the SMA patients, those with MetS tended to report poorer scores on measures of life quality than those without MetS. Patients with MetS were more frequently SMA type 3 and reported significantly worse fatigue than those without.
The researchers noted that MetS is also linked with worse life quality and fatigue in the general population. Still, they said, the results highlight that MetS is common among adults with SMA, suggesting that “age-appropriate screening for MetS in adults with SMA should be considered in clinical care, given the potentially high prevalence of MetS in this population.”
“Given that the prevalence of MetS in our SMA individuals was only slightly higher than the one previously observed in the general population of Germany, future studies in a larger SMA cohort should aim to answer whether this observation represents a normal cross-section of the German population or a higher disease-related prevalence,” the researchers wrote.