2 Minute Medicine Rewind June 29, 2020

Physical exercise associated with reduced risk of chronic pain in university students

1. Higher frequency, intensity, and duration of physical exercise linked to lower risk of chronic pain in Norwegian University students

Evidence Rating: 3 (Average)

Chronic pain is estimated to impact around one-third of the population, and is a leading cause of disability worldwide. There has been mixed evidence on the link between physical activity and chronic pain, in part due to the varied methods in which chronic pain is measured and reported. As well, there is a gap in the literature on this link in young adults, as most chronic pain studies focus on older adults. The current study uses a survey of Norwegian university students to examine the association between the level of physical activity and presence of chronic pain in Norwegian university students, aged 18-35. Chronic pain was measured and reported using the Graphical Index of Pain (GRIP), a digital instrument that maps the entire body and allows users to specifically identify areas of chronic pain. Overall, 54.2% of students reported chronic pain in at least one area of the body. In general, higher levels of physical exercise (higher frequency, longer duration, and higher intensity) were correlated with lower risk of chronic pain. The largest effect in the study came from exercise frequency in men: Those exercising for 2-3 days weekly were 35% less likely to experience chronic pain than those exercising less than once weekly (OR = 0.65, 95% CI = 0.53-0.78). For men, exercising nearly every day did not lower the risk for chronic pain as much as only 2-3 times per week (OR = 0.79, 95% CI = 0.65-0.98), whereas for women, exercising nearly every day lowered the risk for chronic pain the most (OR = 0.79, 95% CI = 0.70-0.88). The strength of these findings were only minimally impacted after adjusting for lifestyle factors, such as alcohol consumption and amount of sleep. The findings of this study show the potential for post-secondary schools to incorporate physical exercise into student life, in order to combat the chronic pain that is often associated with sedentary student behaviours.

Healthy Lifestyle for Prevention of Premature Death Among Users and Nonusers of Common Preventive Medications: A Prospective Study in 2 US Cohorts

1. Healthy lifestyle practices prevent premature death comparably between users and non-users of preventive medications

Evidence Rating: 2 (Good)

In the USA, cardiovascular disease (CVD) and cancer are the two leading causes of death. Preventive medications have been shown to lower the risk of CVD and some forms of cancer, but healthy lifestyle practices can also be preventive, and have been estimated to prevent more than 60% of premature deaths. This prospective cohort study examined how healthy lifestyle practices were associated with premature death in users and non-users of preventive medication. Two cohorts in the US were studied: The Nurses’ Health Study (over 120,000 female nurses) and Health Professionals Follow-up Study (over 50,000 male health professionals). The healthy lifestyle factors in question were BMI, cigarette smoking, alcohol consumption, diet, and physical exercise. The preventive medications examined were aspirin, antihypertensives, and lipid-lowering medications. Both the healthy lifestyle practices and preventive medications were evaluated on a binary scale for each participant. Premature deaths from CVD, cancer, and any cause were examined. The results found that each healthy lifestyle practice was significantly associated with lower all-cause mortality in both the medication users and non-users groups (all P interaction > 0.25). When all 5 factors were pooled into a healthy lifestyle score, the hazards-ratio (HR) for all-cause mortality was 0.82 (95% CI, 0.81-0.82) for users and 0.81 (95% CI, 0.79-0.83) for non-users (P interaction = 0.54). For cancer, the HR was 0.82 (95% CI, 0.81-0.83) in users and 0.82 (95% CI, 0.78-0.85) in non-users (P interaction = 0.94). And for CVD, the HR was 0.81 (95% CI, 0.79-0.82) in users and 0.74 (95% CI, 0.69-0.78) in non-users (P interaction = 0.01). Compared to cancer and all-cause mortalities, healthy lifestyle factors in CVD have the largest difference between the users and non-users group, suggesting that these healthy practices act on mechanisms distinct from the medications. Overall though, these findings show that regardless of medication use, healthy lifestyle practices are a significant factor in preventing premature death, which have implications for how lifestyle changes can be used in conjunction with pharmaceutical therapies to treat chronic disease.

Temporal estimates of case-fatality rate for COVID-19 outbreaks in Canada and the United States

1. Covid-19 case fatality estimated to be 1.6% in Canada and 1.8% in the USA

Evidence Rating: 2 (Good)

Covid-19 has disproportionately affected different areas of the world, not just in the number of cases, but also in the case-fatality rate (CFR): the percentage of deaths in comparison to the number of cases. For instance, estimated CFR values have varied from 0.4% in China to 31.4% in northwest Italy. But the estimation of CFR is confounded by two main factors. The first is the delay between contracting Covid-19 and death: When CFR is calculated at a certain point in time, the deaths resulting from currently active cases cannot be taken into account. The second factor is the underreporting of Covid-19 cases, due to lack of testing and asymptomatic individuals. This retrospective cohort study adjusted for these factors and estimated the CFR for Covid-19 in Canada and the USA, based on data on daily incidence of confirmed COVID-19 cases collected from Jan. 31 to Apr. 22, 2020. The CFR for Canada was 1.6% (95% credible interval of 0.7-3.1%) and the CFR for the USA was 1.8% (95% credible interval of 0.8-3.6%). These estimates are under the assumption that reporting rates for Covid-19 are under 50% in both countries. Overall, this principle of accounting for onset to death lag time and the underreporting of cases is important for future CFR estimates in specific regions, to provide a better understanding of the virulence of the SARS-CoV-2.

Prognostic value of functional capacity in different exercise protocols for heart disease

1. Prognosis of heart disease patients is associated not only with their exercise capacity, but also the type of exercise protocol used

Evidence Rating: 2 (Good)

Exercise testing is a common prognostic measurement used to assess heart disease patients. Exercise capacity, which represents oxygen uptake during exertion, is measured in units of estimated metabolic equivalents (METs), which represent oxygen consumption at rest. The standard exercise protocol is known as the Bruce protocol, but when patients are unable to meet the physical demands of this, the less demanding non-Bruce protocols used instead. This retrospective cohort study examined whether METs consistently predict prognosis of all-cause mortality, between Bruce and non-Bruce protocols. In total, 120 705 patients were examined, with 74 953 undergoing the Bruce protocol, and 45 752 undergoing a non-Bruce protocol. Those undergoing a non-Bruce protocol were more likely to be women, and were on average 10 years older than those in a Bruce protocol. After adjusting for METs, the results showed that patients undergoing a Bruce protocol were associated with a lower risk of mortality, in comparison to those undergoing the less demanding non-Bruce protocols (Hazards Ratio of 0.67; 95% CI, 0.64-0.72; P < 0.001). For both types of protocols though, higher METs were predictive of lower all-cause mortality (Hazards Ratio of 0.46; 95% CI, 0.44-0.48; P < 0.001). Overall, this shows that METs are not transferable between Bruce and non-Bruce protocols: When METs are equivalent in two protocols, the patient in the less demanding protocol has a higher risk of all-cause mortality. The main implication of this study is that the prognosis of a heart disease patient should not only be based on the METs measured from the exercise testing, but also based on the type of exercise protocol chosen.

Brain Natriuretic Peptide for predicting prognoses in patients with worsening renal function and acute heart failure

1. The reduction in Brain Natriuretic Peptide, in conjunction with worsening renal failure, can predict prognosis of patients with acute heart failure

Evidence Rating: 2 (Good)

For patients with acute heart failure (AHF), congestion is one of the primary reasons for hospital admission. A common decongestive treatment employs intravenous loop diuretics: However, this treatment can cause worsening renal function (WRF). In the literature, WRF is associated with poor prognosis for AHF patients when decongestive treatment is unsuccessful, whereas WRF is not associated with poor prognosis when decongestive treatment is successful. Therefore, distinguishing between successful and unsuccessful decongestive treatments is of prognostic importance. The authors of the current study hypothesized that changes in brain natriuretic peptide (BNP), a biomarker associated with greater congestion, would be an indicator of successful decongestive treatments, and therefore a predictor of prognosis in AHF patients with WRF. This retrospective cohort study examined 907 AHF patients from 20 Japanese hospitals. The analyzed factors include the presence of WRF, the reduction in BNP within 48 hours after admission, and the 1 year all-cause mortality. The patients were split into 4 groups: No WRF and low BNP reduction, No WRF and high BNP reduction, WRF and low BNP reduction, and WRF and high BNP reduction. The results showed that only the group with WRF and low BNP reduction had a significantly higher risk of mortality than the group with no WRF and high BNP reduction (Hazard Ratio of 3.34; 95% CI, 1.95-5.73; P < 0.001). Overall, the link between WRF and all-cause mortality is impacted by the amount of reduction in BNP levels. Based on study findings, it appears as though that BNP is a promising indicator for successful decongestive treatments, and is an important factor in predicting prognosis of AHF patients, when combined with WRF.

Image: PD

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