Risk Factors for Falls in DM

Falls are a well-recognized risk factor for patients living with DM. Factors previously linked to falls in DM1 patients include muscle weakness, altered gait properties (including impairment of walking speed), and impaired balance and confidence in balance (Wiles et al., 2006; Hammarén et al., 2014; Hammarén et al., 2015; Radovanović et al., 2016; Jiménez-Moreno et al., 2018). A recent study estimated the risk ratio for falls and associated fractures as 30%-72% and 11%-17%, respectively (Jiménez-Moreno et al., 2018). Data on falls in DM2 patients does not appear to be available. Overall, a better understanding of the incidence, circumstances, and consequences of falls is essential for improving quality of life of those living with DM1 and DM2.

Data from a New Prospective Study

Dr. Corinne Horlings (Radboud University Medical Center and Medical University Innsbruck) and colleagues have completed a prospective study designed to ascertain the properties and consequences of falls in a cohort of DM1 patients (n = 102), DM2 patients (n = 42), and healthy controls (n = 65) (Berends et al., 2019). Data on self-reported falls during the previous year were collected prospectively, while new falls were assessed over a 100-day interval—sample size and study interval were informed by a power analysis.

The research team found that DM1 and DM2 patients both exhibited an increased frequency of falls, falling at rates 7x and 8x that of healthy controls, respectively. Roughly one-third of both DM groups fell at least once, with approximately 17% of each group falling at least twice during the 100-day prospective study period. The majority (two-thirds) of falls occurred inside.

Circumstances and Consequences of Falls

Assessment of the circumstances of falls showed that what the team defines as extrinsic factors—slippery floors or objects on the floor—were associated with the majority (55% in DM1, 46% in DM2) of falls. Most other falls were attributed to intrinsic factors—light-headedness, fatigue, weakness, or stiffness.

For nearly half of falls (40% in DM1, 46% in DM2), patients required assistance to regain standing position. Moreover, injuries resulted from 50% of falls, although most were minor (four patients suffered head trauma). DM1 patients suffering falls profiled as generally older, weaker, had less confidence in balance (often using a walking aid), and had lower DM1-Activ scores. Regression analysis showed that only the DM1-Activ score was associated with increased risk of falling. Profiles of falling versus non-falling DM2 patients could not be differentiated.

Synopsis

The current Clinical Care Recommendations for Adults with Myotonic Dystrophy Type 1 provide this guidance pertinent to falls:

• Moderate- or low-intensity aerobic and resistance exercise, minimizing sedentary activities, if possible. Consider a cardiac evaluation prior to starting a new exercise routine;
• Assistive and adaptive devices such as orthoses, braces, canes, walkers, hand-splints, etc.; and
• Home and environmental modifications as necessary.

The research team described falls as both prevalent and clinically relevant in DM and provided data in support of the Clinical Care Recommendations. They found a substantially increased incidence of falls among DM1 and DM2 patients versus healthy controls, with most falls occurring indoors, in a familiar environment. The high rate of injuries from falls reinforces the risks faced by DM patients. A key gap in the current study is the absence of data on cognitive impairment, potentially a key contributor to falls. The authors acknowledge that the study was not designed to substantiate risk factors for falls. Efforts are needed to develop strategies to mitigate the risks of falls in DM.

References:

Falls and stumbles in myotonic dystrophy.
Wiles CM, Busse ME, Sampson CM, Rogers MT, Fenton-May J, van Deursen R.
J Neurol Neurosurg Psychiatry. 2006 Mar;77(3):393-6. Epub 2005 Sep 30.

Factors of importance for dynamic balance impairment and frequency of falls in individuals with myotonic dystrophy type 1 - a cross-sectional study - including reference values of Timed Up & Go, 10m walk and step test.
Hammarén E, Kjellby-Wendt G, Kowalski J, Lindberg C.
Neuromuscul Disord. 2014 Mar;24(3):207-15. doi: 10.1016/j.nmd.2013.12.003. Epub 2013 Dec 15.

Muscle force, balance and falls in muscular impaired individuals with myotonic dystrophy type 1: a five-year prospective cohort study.
Hammarén E, Kjellby-Wendt G, Lindberg C.
Neuromuscul Disord. 2015 Feb;25(2):141-8. doi: 10.1016/j.nmd.2014.11.004. Epub 2014 Nov 13.

Comparison of temporal and stride characteristics in myotonic dystrophies type 1 and 2 during dual-task walking.
Radovanović S, Perić S, Savić-Pavićević D, Dobričić V, Pešović J, Kostić V, Rakočević-Stojanović V.
Gait Posture. 2016 Feb;44:194-9. doi: 10.1016/j.gaitpost.2015.12.020. Epub 2015 Dec 20.

Falls and resulting fractures in Myotonic Dystrophy: Results from a multinational retrospective survey.
Jiménez-Moreno AC, Raaphorst J, Babačić H, Wood L, van Engelen B, Lochmüller H, Schoser B, Wenninger S.
Neuromuscul Disord. 2018 Mar;28(3):229-235. doi: 10.1016/j.nmd.2017.12.010. Epub 2017 Dec 27.

High incidence of falls in patients with myotonic dystrophy type 1 and 2: A prospective study.
Berends J, Tieleman AA, Horlings CGC, Smulders FHP, Voermans NC, van Engelen BGM, Raaphorst J.
Neuromuscul Disord. 2019 Aug 28. pii: S0960-8966(19)31103-4. doi: 10.1016/j.nmd.2019.08.012. [Epub ahead of print]