Physical activity level and sedentary time determinants among Moroccan hypertensive patients

INTRODUCTION

Hypertension is closely associated with an inactive lifestyle. Physical activity and/or exercise have been shown to delay the development of hypertension. This study aimed to assess the level of physical activity and sedentary time, and its determinants among Moroccan Hypertensive patients.

PATIENTS AND METHODS

A cross-sectional study was conducted between March and July 2019 including 680 hypertensive patients. We administered international physical activity questionnaire in face-to-face interview to assess the level of physical activity and sedentary time.

RESULTS

The results showed that only 43.4% of participants met recommended physical activity levels (≥ 600 MET min/week). Adherence to physical activity recommendations was observed more in male participants (p = 0.035), in participants aged less than 40 years (p = 0.040) and those aged between 41 and 50 years (p = 0.047). The average sedentary time was 37.19 ± 18.92 hours per week. This time was significantly longer in people aged 51 and over, in married, divorced, and widowed people, and in those with low levels of physical activity.

CONCLUSIONS

The level of physical inactivity and the sedentary time was high. In addition, participants with a high-level sedentary lifestyle had a low level of physical activity. Educational actions should be undertaken among this group of participants to prevent the risks associated with inactivity and sedentary behavior.

Heterogeneity of muscle activity during sedentary behavior

Replacing sitting by standing has been hypothesized to reduce the health risks of sitting, based on the assumption that muscles are passive during sitting and active during standing. Interventions have been more effective in overweight (OW) than in normal weight (NW) individuals, but subjects' muscle activities have not been quantified. This study compared quadriceps and hamstring muscle electromyographic (EMG) activity between 57 NW (body mass index (BMI) 22.5 ± 1.5 kg/m², female n = 36) and 27 OW (BMI 28.4 ± 2.9 kg/m², female n = 8) subjects during non-fatiguing standing (15 s, EMG_standing) and sitting (30 min). EMG amplitude was normalized to EMG measured during maximal isometric knee extension and flexion (% EMG_MVC), and sitting muscle inactivity and bursts were determined using 4 thresholds (60% or 90% EMG_standing and 1% or 2% EMG_MVC). Comparisons were adjusted for sex, age, knee extension strength, and the individual threshold. Standing EMG amplitude was 36% higher in OW (1.9% ± 1.5% EMG_MVC) than in NW (1.4% ± 1.4% EMG_MVC, P < 0.05) subjects. During sitting, muscles were inactive 89.8% ± 12.7% of the measurement time with 12.7 ± 14.2 bursts/min across all thresholds. On average, 6% more activity was recorded in NW than in OW individuals for 3 of the 4 thresholds (P < 0.05 for 60% or 90% EMG_standing and 1% EMG_MVC). In conclusion, the OW group had higher muscle activity amplitude during standing but more muscle inactivity during sitting for 3/4 of the thresholds tested. Interventions should test whether the observed heterogeneity in muscle activity affects the potential to gain cardiometabolic benefits from replacing sitting with standing.