A cross sectional descriptive study with further analysis of body mass index, psychosocial correlates and pain as predictors of activities of daily living in African American adult Sickle Cell Disease clinic patients

Pain, psychosocial issues (e.g. depression, anxiety, and general psychological distress), social support deficits and difficulties with activities of daily living (ADLs) are frequently seen in people with sickle cell disease (SCD). People with SCD are experiencing increased longevity due to advances in treatment which may also make them susceptible to acquiring lifestyle influenced diseases (e.g. obesity). Previous work has shown that people with higher BMIs have higher levels of pain and lower levels of ADLs. Our purpose was to describe select medical and psychosocial characteristics of a SCD clinic population and to determine if BMI, psychosocial distress and pain predict impairments in ADLs.

Archival baseline data from 252 adult African American SCD clinic patients were extracted from a larger dataset derived from an ongoing longitudinal study at the Duke Comprehensive Sickle Cell Disease Center. Original study data was collected using medical records review and the Longitudinal Exploration of Medical and Psychosocial Factors in Sickle Cell Disease (LEMPFSCD) which include age, gender, BMI, hydroxyurea treatment status, SCD type, ADLs and validated psychosocial measures including: Symptom Checklist 90-Revised (SCL-90-R) subscales: depression, anxiety, Global Severity Index (GSI); Alford Edwards Social Support Inventory. Pain was measured via the Short Form McGill Pain Inventory (SF-MPQ) subscales: Sensory Pain (SP), Affective Pain (AP) Present Pain Intensity (PPI). One-way ANOVAs were performed using the whole sample to examine variables of interest according to gender, BMI category, SCD type, and receiving vs. not receiving hydroxyurea treatment.Multiple linear regression analyses were conducted on the whole sample and in an overweight/obese (OW/OB) subsample with age; BMI; SCL-90-R depression, anxiety, GSI; SF-MPQ SP, AP, PPI; and SCD severity (severe vs. mild) as predictors of total and physical ADLs.

In the whole sample (N=252), mean BMI was 25.8 kg/m2 (overweight) with 44% classified as overweight or obese. Psychosocial measures (depression, anxiety, GSI) were in the clinical range. Males and females differed in both BMI (P = 0.005) and complex ADLs (P = 0.008) with females having higher BMI and reporting greater impairment in complex ADLs. Impairments in complex ADLs were significantly different across BMI categories (lower in the NW vs. OW; P = 0.021). Patients with SCD types HbSβ+ thalassemia and HbSC had higher BMIs than those with HbSS type (P < 0.001). Patients not receiving hydroxyurea treatment were older (P = 0.012) and had higher BMI (P = 0.013), compared to those receiving hydroxyurea treatment. In predictive models using the whole sample, higher AP and age predicted impairments in total ADLs and AP predicted impairment in physical ADLs. In the OW/OB subsample, AP, age and SCD severity predicted impairments in total and physical ADLs.

Our finding of BMI in the overweight range is relatively novel as few have documented this previously. This warrants further investigation. Our finding of a consistent relationship of AP to ADL impairment suggests that focusing on the affective pain perhaps through multidisciplinary behavioral pain management programs, may improve functioning.