Differences in back extensor strength between smokers and nonsmokers with and without low back pain

"It frees your body from that pain thought": A mixed-methods exploration of patterns, contexts, and experiences of cannabis use for pain in rural communities

U.S. adults increasingly report using cannabis to manage chronic pain and rural areas have inadequate comprehensive pain management. Using mixed methods, we aimed to understand how and why some rural adults use cannabis for pain, including within the context of co-use with opioids. Participants (N = 14, Oklahoma) were rural-dwelling adults who used tobacco and ≥1 other substance, including cannabis and opioids, ≥3 days per week. Participants completed 14 days of ecological momentary assessment (EMA) regarding substance use and subsequent in-depth interviews discussing maps of their substance use reports. Half (7/14) described cannabis use for chronic pain, and most of these (85%) reported use on ≥75% of EMA days. The most frequently reported cannabis use motive was therapeutic/medicinal (90% of use reports). Most reports were of combusted cannabis (88% of use reports) at home (99% of use reports). Same-day use of cannabis and opioids was relatively common (45% of daily surveys), but seemingly not within close temporal proximity. Interview narratives characterized cannabis as modifying pain-adjacent factors (eg, thoughts), not eliminating pain itself. They recounted using a repertoire of substances to manage different pain dimensions (eg, intensity, quality) and balance perceived trade-offs of different substances. Participants described high medical cannabis access, low pain specialist access, and most physicians as unwilling to discuss cannabis for pain. The findings suggest that rural-dwelling patients could benefit from increased access to comprehensive pain management, having cannabis addressed within pain management provider discussions, and that risks and benefits of cannabis use for pain must be better established. PERSPECTIVE: This study used a geographically explicit EMA mixed method to gather rich, intensive pilot data on cannabis use and co-use for chronic pain in rural Oklahoma. It provides unique insights to inform future research on cannabis use among a vulnerable and understudied subgroup of adults with pain-rural residents.

Prevalence and risk factors of chronic low back pain in university athletes: a cross-sectional study

AIM

This study aimed to establish the prevalence of chronic low back pain (CLBP) in university-level athletes and to examine the influence of age, sex, body mass index (BMI), sports discipline, sleep, anxiety, and depression on CLBP. The secondary purpose was to check the association of certain variables in athletes having CLBP with the sports discipline and chronicity of LBP.

METHODS

A total of 340 players (100% response rate) from different sports, aged 18-30 years with at least 1 year of participation in sports at the university level were screened for the present study. The subjects completed a detailed, semi-structured questionnaire that gathered data regarding their demographic variables, personal and pain-related factors. The study was registered on the clinical trials registry, India (CTRI/2021/09/036675).

RESULTS

The results revealed the sport-wise point prevalence as follows: cricket (18.5%), basketball (15.6%), volleyball (20.0%), football (11.4%), badminton (7.7%) and tennis (7.7%). A higher number of years at university-level participation (>4 years), smoking, anxiety and BMI (>25 kg/m²) are risk factors for CLBP. The type of LBP, the intensity of the pain (current and last week), variation of the pain intensity, disability, intake of oral medications, physiotherapy for CLBP, number of missed days of training and number of missed matches are not significantly related to the chronicity of LBP or the sports discipline. Only the number of missed days of training had a significant association with the chronicity of LBP.

CONCLUSIONS

CLBP is a common complaint in Indian university athletes, and our findings indicate the necessity for a specific prevention program.

Fourteen days of smoking cessation improves muscle fatigue resistance and reverses markers of systemic inflammation

Cigarette smoking has a negative effect on respiratory and skeletal muscle function and is a risk factor for various chronic diseases. To assess the effects of 14 days of smoking cessation on respiratory and skeletal muscle function, markers of inflammation and oxidative stress in humans. Spirometry, skeletal muscle function, circulating carboxyhaemoglobin levels, advanced glycation end products (AGEs), markers of oxidative stress and serum cytokines were measured in 38 non-smokers, and in 48 cigarette smokers at baseline and after 14 days of smoking cessation. Peak expiratory flow (p = 0.004) and forced expiratory volume in 1 s/forced vital capacity (p = 0.037) were lower in smokers compared to non-smokers but did not change significantly after smoking cessation. Smoking cessation increased skeletal muscle fatigue resistance (p < 0.001). Haemoglobin content, haematocrit, carboxyhaemoglobin, total AGEs, malondialdehyde, TNF-α, IL-2, IL-4, IL-6 and IL-10 (p < 0.05) levels were higher, and total antioxidant status (TAS), IL-12p70 and eosinophil numbers were lower (p < 0.05) in smokers. IL-4, IL-6, IL-10 and IL-12p70 had returned towards levels seen in non-smokers after 14 days smoking cessation (p < 0.05), and IL-2 and TNF-α showed a similar pattern but had not yet fully returned to levels seen in non-smokers. Haemoglobin, haematocrit, eosinophil count, AGEs, MDA and TAS did not significantly change with smoking cessation. Two weeks of smoking cessation was accompanied with an improved muscle fatigue resistance and a reduction in low-grade systemic inflammation in smokers.

Muscle Dysfunction in Smokers and Patients With Mild COPD: A SYSTEMATIC REVIEW

PURPOSE

To describe and discuss the available evidence in the literature concerning muscle function and the association between smoking and muscle dysfunction in smokers and patients with mild chronic obstructive pulmonary disease (COPD).

METHODS

The literature search involved the following databases: PubMed, Pedro, CINAHL, Cochrane Library, Lilacs, and EMBASE. Studies were included if they investigated muscle strength and/or endurance and/or cross-sectional area (CSA) in smokers and/or patients with COPD classified as Global Initiative for Obstructive Lung Disease (GOLD) I and without lung cancer. Two authors screened and identified the studies for inclusion.

RESULTS

Eighteen studies were identified. Some studies found lower values in a variety of muscle strength variables in smokers compared with nonsmoking controls, whereas others found similar values between these groups. When comparing patients with COPD classified as GOLD I with smokers, COPD patients showed lower muscle strength. Two studies found no differences in muscle CSA between smokers compared with nonsmoking controls. Some preliminary evidence also shows that patients with COPD classified as GOLD I had lower CSA in comparison with smokers.

CONCLUSION

Results concerning muscle dysfunction in smokers are divergent, since some studies have shown worse results in a variety of muscle strength variables in smokers compared with nonsmoking controls, whereas other studies have not. Moreover, there is rather preliminary evidence indicating worse muscle dysfunction and lower CSA in patients with mild COPD in comparison with healthy (or non-COPD) smokers.

Associations Between Low Back Pain and Muscle-strengthening Activity in U.S. Adults

STUDY DESIGN

This was a cross-sectional study.

OBJECTIVE

The primary aim of the study was to examine the association between low back pain (LBP) and muscle-strengthening activity (MSA) among U.S. adults using gender-stratified analyses.

SUMMARY OF BACKGROUND DATA

LBP is a common medical condition that impacts quality of life and professional productivity and increases the financial burden on the health care system by augmenting medical treatment costs. Previous studies analyzing gender-dependent relationships between MSA and LBP have produced mixed results.

METHODS

Our sample included 12,721 participants from the 1999 to 2004 National Health and Nutrition Examination Survey (NHANES). Participants were categorized into one of three levels of self-reported MSA: no MSA, insufficient MSA (1 day/wk), or meeting the 2008 Department of Health and Human Services (DHHS) recommendation for MSA (≥2 days/wk).

RESULTS

Gender-stratified analyses revealed significantly lower odds of reporting LBP among women [odds ratio (OR) 0.82, 95% confidence interval (CI) 0.70-0.96, P = 0.03] and men (OR 0.86; 95% CI 0.70-0.96, P = 0.01) who reported amounts of MSA that met the DHHS recommendation compared with those reporting no MSA. Following adjustment for smoking status, the odds remained significant among women (P = 0.03) but not among men (P = 0.21).

CONCLUSION

These findings indicate that engaging in MSA at least 2 days/wk is associated with lower odds of LBP and that smoking may be an important mediating factor that should be considered in future LBP research.

LEVEL OF EVIDENCE

4.

Tobacco Use and Its Health Effects among Professional Athletes in Qatar

The objective of the study was to determine the effects of tobacco use on selected markers of health and lung function in professional athletes. A total of 108 male professional athletes participated in the study from ten ball game teams in the same sport league in Qatar (age = 26.4 ± 5.1 yrs, height = 190.6 ± 11.9 cm, and weight = 91.5 ± 16.4 kg). The athletes have been playing professionally for about 6.3 years on average. In addition to demographic and tobacco use status, the following clinical variables were measured: resting blood pressure, heart rate, FVC, FEV₁ sec, and PEF. The prevalence of tobacco use among the athletes was 27.7%. The FVC, FVC%, and FEV₁% were significantly lower among the smokers compared to the nonsmokers (p = 0.003, 0.044, and 0.001, resp.). There were no significant differences between cigarettes smokers and nonsmokers in BP, HR, FEV₁, FEV₁/FVC, PEF, and PEF%. Similarly, those who smoked shisha had lower FEV₁% values as compared to those who did not smoke shisha (p = 0.001). The decrease of FEV₁ and FVC among smokers compared to nonsmokers is similar to what has been reported in the literature about other populations.

A Health- and Resource-Oriented Perspective on NSLBP

Nonspecific low back pain (NSLBP) is an important health issue of our time. Personal as well as economic factors, like suffering pain and experiencing disability on the one hand and enormous and still increasing costs to the economy and society on the other hand, display the importance of the matter. Tremendous research has been conducted in the last few decades on NSLBP. A PubMed search (June 17, 2013) on “low back pain” provided 22,980 hits, and when specifying for “low back pain, systematic review,” 3,134 hits were still generated. Most research has been done examining the development, risk factors, or therapeutic measures of NSLBP, but hardly any literature exists on resources related to NSLBP. The aims of this review are twofold. In order to shade light on the salutogenetic approach of NSLBP, and thus to focus on health instead of illness, the first aim is to facilitate the understanding of which therapeutic measures enhance the ability to cope with chronic NSLBP and enable (more) normal functioning in life. The second aim is to stimulate the understanding of resources protecting against the onset of NSLBP or against the development of chronic NSLBP and its resulting work absence.

The effect of cigarette smoking history on muscular and cardiorespiratory endurance

The purpose of this study was to investigate the effect of cigarette smoking history on physical fitness in younger adults. Small, insignificant differences in BMI between non-smokers and smokers were shown regardless of cigarette smoking history duration. Although the differences in muscular endurance increased in the samples with progressing cigarette smoking history duration, a highly significant difference in aerobic endurance was observed between the group of non-smokers and smokers with a history of smoking up to 5 years and persisted at the same level in smokers with a history of smoking for longer than 10 years.

The longitudinal relation between smoking and muscle strength in healthy adults

AIM

To assess longitudinally whether smoking tobacco is related to muscle strength in healthy adults and to assess the influence of lifestyle covariates on this relation.

METHODS

Data were obtained from the observational Amsterdam Growth and Health Longitudinal Study, with four repeated measurements at the ages of 21 (n = 181), 27 (n = 144), 32 (n = 426) and 36 (n = 373) years. Knee muscle strength (KMS) was measured at an angle of 300° per second. Smoking and the covariates physical activity and dietary intake were assessed with a questionnaire. Other covariates included physical fitness and body fat percentage. Cardiopulmonary fitness was assessed with a maximal running test and body fatness with skinfold measurements. Sex-specific longitudinal analyses were carried out using generalized estimating equations.

RESULTS

In men and women, an inverse relationship between smoking tobacco and KMS was found. Smoking 100 g of tobacco a week resulted in a reduction of 2.9% in KMS in men and a reduction of 5.0% in women. This relation existed largely independently of lifestyle covariates.

CONCLUSION

This study indicates that smoking is inversely related to skeletal muscle strength in healthy adults.

Muscular fitness in relation to physical activity and television viewing among young adults

PURPOSE

To study how time spent in physical activity and that in television (TV) viewing are associated with muscular fitness among young adults.

METHODS

The study population consisted of a cross-sectional sample of 381 males and 493 females aged 19.1 yr (SD 0.3) from the Northern Finland Birth Cohort 1986. Muscular fitness was measured by trunk muscle strength tests (trunk extension, flexion, and rotation) and jumping height test. Time spent on moderate- to vigorous-intensity physical activity and on TV viewing was self-reported by a questionnaire.

RESULTS

The most physically active young adults performed significantly better in most trunk muscle strength tests and the jumping test than the least active subjects. The mean difference between the most and least active groups was at minimum 1.6 kg (95% confidence interval (CI) = -0.5 to 3.7) and at maximum 10.6 kg (95% CI = 4.7-16.5) for different trunk muscle strength tests and at minimum 4.4 cm (95% CI = 2.7-6.1) for the jumping height test. Males and females who watched TV for >or=2 h x d(-1) performed significantly worse in trunk extension and flexion tests and females also performed worse in the jumping test compared with those who watched TV <2 h x d(-1), independent of their physical activity level. The mean difference between low and high TV users was at minimum -3.8 kg (95% CI = -6.7 to -0.9) for trunk extension and flexion strength and -1.2 cm (95% CI = -2.0 to -0.4) for jumping height in females.

CONCLUSIONS

Among young adults, daily TV viewing for >or=2 h, irrespective of physical activity level, was associated with poorer muscular fitness.

Skeletal muscle properties and fatigue resistance in relation to smoking history

Although smoking-related diseases, such as chronic obstructive pulmonary disease (COPD), are often accompanied by increased peripheral muscle fatigability, the extent to which this is a feature of the disease or a direct effect of smoking per se is not known. Skeletal muscle function was investigated in terms of maximal voluntary isometric torque, activation, contractile properties and fatigability, using electrically evoked contractions of the quadriceps muscle of 40 smokers [19 men and 21 women; mean (SD) cigarette pack years: 9.9 (10.7)] and age- and physical activity level matched non-smokers (22 men and 23 women). Maximal strength and isometric contractile speed did not differ significantly between smokers and non-smokers. Muscle fatigue (measured as torque decline during a series of repetitive contractions) was greater in smokers (P = 0.014), but did not correlate with cigarette pack years (r = 0.094, P = 0.615), cigarettes smoked per day (r = 10.092, P = 0.628), respiratory function (%FEV_1pred) (r = −0.187, P = 0.416), or physical activity level (r = −0.029, P = 0.877). While muscle mass and contractile properties are similar in smokers and non-smokers, smokers do suffer from greater peripheral muscle fatigue. The observation that the cigarette smoking history did not correlate with fatigability suggests that the effect is either acute and/or reaches a ceiling, rather than being cumulative. An acute and reversible effect of smoking could be caused by carbon monoxide and/or other substances in smoke hampering oxygen delivery and mitochondrial function.

Association of activity limitations and lower-limb explosive extensor power in ambulatory people with stroke

OBJECTIVE

To determine whether the explosive lower-limb extensor power of the affected and unaffected sides, and any asymmetry, are associated with activity limitations after stroke.

DESIGN

Cross-sectional observational study of baseline data from a randomized controlled trial.

SETTING

Measurements made in a hospital clinical research facility.

PARTICIPANTS

Community-dwelling (N=66) subjects with stroke who were independently ambulatory. Subjects' mean age was 72+/-10 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The lower-limb extensor power of each lower limb (in W/kg), performance of specific functional activities (comfortable walking velocity, Functional Reach Test, chair-rise time, Timed Up & Go test), and global indices of activity limitation (FIM instrument, Rivermead Mobility Index, Nottingham Extended Activities of Daily Living).

RESULTS

Low lower-limb extensor power in either lower limb was the principal factor from among the confounders we recorded that significantly (R(2) range, .21-.46) predicted the limitation of specific functional activities, and low lower-limb extensor power in either lower limb was the principal predictive factor for global indices of activity limitation (R(2) range, .13-.38). The degree of asymmetry of lower-limb extensor power between legs was low and had little or no predictive value.

CONCLUSIONS

In ambulatory persons with stroke, activity limitations are associated with deficits in lower-limb extensor power of both lower limbs, and not the severity of any residual asymmetry. These findings suggest that interventions to increase lower-limb extensor power in both lower limbs might reduce activity limitations after stroke.

Muscle fatigue resistance during stimulated contractions is reduced in young male smokers

AIM

To determine whether muscle function is compromised in healthy smokers in comparison with activity-matched non-smokers.

METHODS

Nine male smokers (aged 22.2 +/- 2.5 years: mean +/- SD) with a smoking history of 2.5 +/- 3.1 pack years, and ten male control participants (25.4 +/- 2.9 years) matched for physical activity level participated in this study. Knee extensor strength was measured using isometric maximal voluntary contractions. Voluntary activation of the quadriceps and co-activation of the biceps femoris were determined using interpolated twitches and surface electromyography respectively. The frequency-torque relationship and fatigue resistance were assessed with electrically evoked contractions. A fatigue index was determined as the ratio of final torque to initial torque during a series of isometric contractions (2 min; 30 Hz; 1 s contraction/1 s rest). Quadriceps anatomical cross sectional area was measured with MRI at 50% of femur length.

RESULTS

Maximal voluntary contraction torque, quadriceps anatomical cross sectional area, knee extensor torque/quadriceps cross sectional area, activation, co-activation and force-frequency relationship were similar, whereas the fatigue index was 17% lower in smokers than non-smokers.

CONCLUSION

In young men smoking does not significantly affect quadriceps muscle mass and contractile properties, but does reduce fatigue resistance of the quadriceps muscle, which was not attributable to differences in physical activity.