Quality of Life in Obesity is Determined by Health, Not Size
Over the past few days, I have been posting on the results of the APPLES study – a prospective 24-month assessment of patients wait-listed for or undergoing treatment at a publicly funded bariatric centre in Alberta, Canada.
In a separate analysis, just released in OBESITY, Lindsey Warkentin and colleagues present the baseline quality of life (QoL) data for the 500 patients enrolled in this study.
As noted previously, the average BMI of participants in this study was 47.9, 90% were female with an average age of 43.
Quality of life was assessed at the time of enrolment in the study using several standardized and validated instruments (Short-Form (SF)-12 [Physical (PCS) and Mental (MCS) component summary scores], EuroQol (EQ)-5D [Index and Visual Analog Scale (VAS)], and Impact of Weight on Quality of Life (IWQOL)-Lite).
As may be expected, the overall QoL of these patients was substantially lower than the general population in Alberta.
Thus, the mean physical and mental component summary scores in the SF-12, were both substantially lower (by about 10 points) than general population scores in Albertan adults. Similar reductions in QoL were found with the other instruments.
Key predictors of poor QoL included fibromyalgia, pain, depression, sleep apnea, coronary artery disease and stroke (among others).
Interestingly, however, despite a wide range of body weights in this study, BMI itself had almost no predictive value in terms of health status or quality of life.
This is perhaps not surprising, as we have previously shown that BMI alone is not a reliable or even sensitive measure of health (which is why we developed the Edmonton Obesity Staging System to better characterize the health status of individuals with obesity).
Thus, it is the actual presence of related illnesses that determine the quality of life – not simply the amount of excess body fat.
This finding has important implications for treatment and prioritization.
For one, as noted previously, BMI or other measures of size alone are a poor guide as to how sick your patient is – determining the health impact of excess weight actually requires assessing the presence of physical and mental comorbidities (of which there are many).
Conversely, as QoL is largely dependent on the presence of related illnesses – it may well be that treating and controlling these illnesses may have a great impact (and perhaps be far more effective and practical) than simply focussing on weight loss.
Thus, for example, it may be far more cost effective and practical to treat the symptoms of severe osteoarthritis (by replacing a knee or hip) or the symptoms of sleep apnea (with CPAP) than simply focussing all attention on dropping the numbers on the scale.
As much as losing weight may be the preferred option (if we had better treatments), better management of relevant comorbidities could perhaps result in substantial greater improvements in health-related quality of life than struggling to lose a few pounds.
Thus, an important tenet of bariatric care has to focus on better managing the health problems that obese patients present with even if significant and persistent weight loss remains elusive in most patients.
Bariatric care is so more than just running a weight-loss clinic.
Warkentin LM, Majumdar SR, Johnson JA, Agborsangaya CB, Rueda-Clausen C, Sharma AM, Klarenbach SW, Birch DW, Karmali S, McCargar L, Fassbender K, & Padwal RS (2014). Predictors of health-related quality of life in 500 severely obese patients: An assessment using three validated instruments. Obesity (Silver Spring, Md.) PMID: 24415405