More age-related health problems affect SMA patients earlier: Study
30 conditions disproportionately affect SMA patients at younger ages: US study
Adults with spinal muscular atrophy (SMA) experience more health problems affecting a range of bodily systems compared with the general population, according to a U.S. healthcare claims analysis.
A total of 30 conditions examined in the study, many of which are associated with older age in the general population, appear to disproportionately affect SMA patients at a younger age. The conditions included cardiovascular conditions, bone problems, gastrointestinal issues, and mental health disorders.
“These findings highlight the need for clinical awareness of a high-early burden of morbidities as children with SMA age into and throughout their adult years, ” researchers wrote.
The study, “Prevalence of morbidities across the lifespan for adults with spinal muscular atrophy: a retrospective cohort study,” was published in the Orphanet Journal of Rare Diseases.
SMA patients living longer with emergence of 3 treatments in the last decade
Within the last decade, three disease-modifying therapies for SMA have emerged: Spinraza (nusinersen), Zolgensma (onasemnogene abeparvovec), and Evrysdi (risdiplam). Their use is expected to drastically change the SMA landscape, with patients living longer and healthier lives.
As such, the care priorities for SMA patients might change in the coming years. Instead of primarily targeting the main SMA symptoms (e.g. muscular problems), treatment might instead need to shift focus toward aging-related conditions that arise as patients live longer, according to the scientists.
However, there is currently a lack of information about how these age-related conditions, or morbidities, naturally evolve in untreated SMA patients.
“Identifying morbidity profiles across physiologic systems as individuals with SMA age into and throughout their adult years is necessary to assist in prioritizing clinical care to manage the person with SMA,” the researchers wrote.
In the study, they examined healthcare claims data in the U.S. to establish the prevalence of various health conditions among adults with or without SMA. Data were obtained from the period from 2008-2016, in the so-called “pre-treatment era” before SMA-targeted therapies.
The analysis involved 2,427 adults with SMA (mean age of 59.7), as well as 484,528 adults without SMA who were matched to the patients in terms of demographics, geography, and date.
A total of 30 morbidities were examined, spanning cardiovascular, metabolic, musculoskeletal, respiratory, gastrointestinal, liver, kidney, cancer, and mental health conditions.
These findings highlight the need for clinical awareness of a high-early burden of morbidities as children with SMA age into and throughout their adult years.
Higher prevalence of 30 morbidities found in adults with SMA
The most common morbidities among SMA patients, affecting at least 25% of men and women, were high blood pressure, lung disease, bone problems, anemia, heart rhythm changes, fluid/electrolyte disorders, and diabetes.
In statistical analyses, adults with SMA were found to have a higher prevalence of all 30 evaluated morbidities compared with adults without SMA. This ranged from 1.6-fold higher odds of low thyroid gland function (hypothyroidism) to a 24.3-fold increase in the likelihood of having intellectual disabilities.
Generally speaking, the risk of most morbidities (24 of 30) was higher in the youngest group of SMA patients (ages 18-39) compared to their age-matched controls than in older groups, which suggests that “morbidity onset may occur earlier in the adult lifespan for those with vs. without SMA,” according to the researchers.
Nevertheless, SMA patients were still at a significantly higher risk of the morbidities than the controls even in the oldest evaluated age group (75 and older).
These findings may be particularly important in light of the fact that many of the evaluated conditions are considered age-related, meaning they often emerge in older adults in the general population.
As such, they “may be overlooked clinically for young and middle-aged adults with SMA, thus missing out on critical opportunities for early detection and prevention,” the researchers wrote.
Sex also significantly influenced the morbidity risk in SMA patients for 13 conditions.
Although both men and women with SMA had higher odds of these morbidities than their sex-matched controls, the odds tended to be higher in women for cardiovascular diseases and sleep disorders. On the other hand, men with SMA tended to have a higher risk for bone fragility, dementia, mental health disorders, and nutrition/gastrointestinal disorders.
SMA patients had higher odds of having other health problems
On average, female SMA patients had five morbidities and male patients had four. Healthy women had a median of two and healthy men had one.
Statistical analyses generally indicated that SMA patients had higher odds of having at least one morbidity, and a higher number of morbidities per person than controls.
The strength of these relationships tended to decline with age, meaning the morbidity burden became more similar between SMA patients and healthy people as they aged.
Altogether, “adults with SMA had a higher and earlier prevalence of a variety of morbidities across physiological systems and mental health disorders,” the researchers wrote.
“Increasing clinical awareness of the high-early prevalence and [odds] of morbidities, improving screening strategies, and developing appropriate referral systems may help to reduce the burden of morbidities for this vulnerable population,” the team concluded.