A Simple Scale for Screening Lower-Extremity Arterial Disease as a Possible Cause of Low Back Pain: a Cross-sectional Study Among 542 Subjects

Pain Characteristics, Cardiovascular Risk Factors, and Cardiovascular Disease

BACKGROUND

There is unclear evidence that chronic pain may increase the risk of cardiovascular disease (CVD) incidence and mortality. This work evaluated the association between chronic pain, incidence of CVD and changes in CVD risk factors.

METHODS

Cohort of 1091 community-dwelling individuals ≥60years, free from CVD at baseline, followed up for 6 years. Data on psychosocial factors and CVD risk factors was obtained through validated questionnaires and laboratory measurements. A pain scale ranging from 0 (no pain) to 6 (worst pain) was created according to pain frequency, location and intensity.

RESULTS

The cumulative incidence of CVD was 4.2% at 3 years, and 7.7% at 5-years of follow-up. Compared to individuals without pain in the first 3 years (2012-2015), those with maintained scores ≥2 showed a mean reduction of 3.57 (-5.77,-1.37) METs-h/week in recreational physical activity; a 0.38-point (0.04,0.73) increase in psychological distress; and a 1.79 (1.03,3.11) higher odds of poor sleep. These associations held in the second follow-up period, when individuals with maintained pain also worsened their diet quality. A 1-point increase in the pain scale in 2012 was associated with a 1.21 (1.03,1.42) and 1.18 (0.97,1.44) increased CVD incidence in 2015 and 2017, respectively; none of the studied factors mediated this relationship.

CONCLUSIONS

Older adults with chronic pain show important reductions in recreational physical activity and deterioration in mental health, sleep and diet quality, which may well aggravate pain. Future studies should evaluate whether these factors mediate the increased risk of CVD observed in older adults with chronic pain.

Investigation of arterial claudication with transcutaneous oxygen pressure at exercise: Interests and limits

Transcutaneous oxygen pressure (TcpO2) measurement has been used for years at rest in patients with lower extremity artery disease. It was proposed for exercise testing (Ex-TcpO2) in the 80ies to evaluate regional blood flow impairment (RBFI) at the proximal and distal levels simultaneously and on both sides, in case of claudication. It was suggested that the use of a chest electrode was mandatory to show that decreases in TcpO2 at the limb level result from limb RBFI and not from a systemic pO2 decrease of cardiopulmonary origin (exercise-induced hypoxemia). Unfortunately, a major pitfall of Ex-TcpO2 was the low absolute reliability of the regional perfusion index (RPI: ratio of limb to chest values) and the technique was almost abandoned until 2003, when the DROP index (Decrease from rest of oxygen pressure: limb changes minus chest changes from rest) was proposed. The DROP mathematical formula makes Tcpo2 results independent from the absolute pO₂ starting values, improving reliability of Ex-TcpO2 as compared to the RPI. Since then, Ex-TcpO2 has been of renewed interest. The present paper addresses the physiology of Ex-TcpO2, interpretation of its results, and common misunderstandings about its use.