TY - JOUR
T1 - Nocturnal leg cramps
T2 - Prevalence and associations with demographics, sleep disturbance symptoms, medical conditions, and cardiometabolic risk factors
AU - Grandner, Michael A.
AU - Winkelman, John W.
N1 - Funding Information:
I have read the journal's policy and the authors of this manuscript have the following competing interests: Dr. Winkelman is a consultant for Merck and Flex Pharma. He has provided expert testimony for Cantor Colburn. He receives royalties from UpToDate. He has received research grants from Luitpold Pharmaceuticals, Xenoport, UCB Pharma, NeuroMetrix, and NIMH. Dr. Grandner is a consultant for FitBit and is on the Scientific Advisory Board for CurAegis Technologies. He has provided expert testimony for Morrison Foerster. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
Funding Information:
The authors wish to thank Dr. Susan Redline for her contributions to editing the manuscript, as well as Nicholas Jackson for input on statistical models. Dr. Winkelman is a consultant for Merck and Flex Pharma, has provided expert testimony for Cantor Colburn, receives royalties from UpToDate, and has received research grants from Luitpold Pharmaceuticals, Xenoport, UCB Pharma, NeuroMetrix, and NIMH. Dr. Grandner is a consultant for FitBit and is on the Scientific Advisory Board for CurAegis Technologies. He has provided expert testimony for Morrison Foerster. This abstract was presented at the 2016 APSS SLEEP meeting.
Publisher Copyright:
© 2017 Grandner, Winkelman. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2017/6
Y1 - 2017/6
N2 - Background: Nocturnal leg cramps (NLC) are common and poorly understood. Objective: To determine the prevalence of NLC and associations with cardiometabolic, sleep, and behavioral risk factors in the US population. Design: Cross-sectional epidemiology. Participants: National Health and Nutrition Examination Survey, 2005-2006 and 2007-2008 waves. Main outcome(s) and measure(s): NLC were assessed with, "In the past month, how often did you have leg cramps while trying to sleep?" Responses were categorized as None, Mild, or Moderate-Severe. Demographics, medical history, sleep disturbances, and cardiometabolic risk factors were evaluated using the 2005-2006 dataset. Variables that demonstrated significant relationships to NLC after adjusting for age, sex, education, and BMI were assessed in the 2007-2008 dataset. Variables that were still significant were entered into a forward stepwise regression model combining both waves, to determine which variables best explained the variance in NLC. Results: Prevalence was 24-25% reporting mild and 6% reporting moderate-severe NLC. NLC increased with age, lower education, unemployment, shorter sleep duration, all assessed sleep symptoms (nocturnal "leg jerks", snoring, snorting/gasping, difficulty falling asleep, difficulty maintaining sleep, non-restorative sleep, sleepiness, use of sleep medications), higher BMI, smoking, medical history (hypertension, heart failure, angina, stroke, arthritis, respiratory disease, and cancer), depression symptoms, and biomarkers (CRP, HbA1c, calcium, cadmium, red blood cells). Stepwise analysis showed that moderate-severe nocturnal leg cramps were associated with (in decreasing order of partial R2 ): leg jerks, poor overall health, arthritis, difficulty falling asleep, age, nonrestorative sleep, red blood cell count, lower education, angina, and difficulty maintaining sleep. Conclusions and relevance: Based on this first large, representative study, NLC occurring >5x per month are reported by 6% of the adult US population. Sleep disturbance symptoms and health conditions are associated with higher frequency of NLC, suggesting that NLC is a marker, and possibly contributor, to poor sleep and general health.
AB - Background: Nocturnal leg cramps (NLC) are common and poorly understood. Objective: To determine the prevalence of NLC and associations with cardiometabolic, sleep, and behavioral risk factors in the US population. Design: Cross-sectional epidemiology. Participants: National Health and Nutrition Examination Survey, 2005-2006 and 2007-2008 waves. Main outcome(s) and measure(s): NLC were assessed with, "In the past month, how often did you have leg cramps while trying to sleep?" Responses were categorized as None, Mild, or Moderate-Severe. Demographics, medical history, sleep disturbances, and cardiometabolic risk factors were evaluated using the 2005-2006 dataset. Variables that demonstrated significant relationships to NLC after adjusting for age, sex, education, and BMI were assessed in the 2007-2008 dataset. Variables that were still significant were entered into a forward stepwise regression model combining both waves, to determine which variables best explained the variance in NLC. Results: Prevalence was 24-25% reporting mild and 6% reporting moderate-severe NLC. NLC increased with age, lower education, unemployment, shorter sleep duration, all assessed sleep symptoms (nocturnal "leg jerks", snoring, snorting/gasping, difficulty falling asleep, difficulty maintaining sleep, non-restorative sleep, sleepiness, use of sleep medications), higher BMI, smoking, medical history (hypertension, heart failure, angina, stroke, arthritis, respiratory disease, and cancer), depression symptoms, and biomarkers (CRP, HbA1c, calcium, cadmium, red blood cells). Stepwise analysis showed that moderate-severe nocturnal leg cramps were associated with (in decreasing order of partial R2 ): leg jerks, poor overall health, arthritis, difficulty falling asleep, age, nonrestorative sleep, red blood cell count, lower education, angina, and difficulty maintaining sleep. Conclusions and relevance: Based on this first large, representative study, NLC occurring >5x per month are reported by 6% of the adult US population. Sleep disturbance symptoms and health conditions are associated with higher frequency of NLC, suggesting that NLC is a marker, and possibly contributor, to poor sleep and general health.
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U2 - 10.1371/journal.pone.0178465
DO - 10.1371/journal.pone.0178465
M3 - Article
C2 - 28586374
AN - SCOPUS:85020162802
SN - 1932-6203
VL - 12
JO - PloS one
JF - PloS one
IS - 6
M1 - e0178465
ER -