Dados do Trabalho

Título

SLEEP REGULARITY AND PERIPHERAL MUSCLE STRENGTH IN INDIVIDUALS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD).

Introdução

Complaints about sleep are frequent among individuals with chronic obstructive pulmonary disease (COPD). Poor sleep has been linked to various adverse effects in this group, including decreased levels of physical activity, exercise capacity and muscle strength. Although there is already a known connection between sleep and peripheral muscle strength in individuals with COPD, this is limited to sleep quality, indicating a gap in the literature concerning other sleep factors, such as regularity.

Objetivo

To examine the relationship between peripheral muscle strength of upper and lower limbs and sleep regularity in individuals with COPD. The secondary objective was to verify the degree of influence of sleep regularity on peripheral muscle strength.

Métodos

In this cross-sectional analysis, individuals with COPD underwent assessments for lung function via spirometry, upper limb muscle strength through handgrip, and lower limb muscle strength via maximal voluntary isometric muscle contraction of the quadriceps femoris. Sleep was objectively evaluated using Actiwatch over a period of 7 consecutive days, and regularity was determined by calculating the standard deviation. Statistical analysis included the Shapiro-Wilk test, Pearson or Spearman correlation coefficients and simple linear regressions. The SPSS 20.0 software was utilized with a significance level set at P≤0.05.

Resultados

32 individuals diagnosed with COPD were analyzed (16 men; age 69±8 years; BMI 28±5 kg/m2; FEV1 59±19%pred). Upper limb strength correlated significantly with the regularity of total time in bed (r=-0.38, p=0.033), time wake after sleep onset (WASO) (r=-0.36, p=0.050) and showed a trend with the regularity of total sleep time (r=-0.33, p=0.073). Lower limb strength was associated with the regularity of sleep efficiency (r=-0.42, p=0.024), WASO (r=-0.49, p=0.007) and total sleep duration (r=-0.45, p=0.014). It was possible to conduct a simple linear regression analysis between handgrip strength and WASO, with R2=0.103). When considering femoral quadriceps strength, significant associations could be identified with all the variables previously correlated, with R2 values ranging from 0.144 to 0.215.

Conclusões

In individuals with COPD, sleep regularity associates moderately with peripheral muscle strength both of the upper and lower limbs.

Palavras -chave

Chronic obstructive pulmonary disease; Sleep; Muscle strength.