There is limited evidence in the world literature on weight perception variability in cardiac patients. The current study sample showed a representative distribution of socio-economic characteristics of a Sri Lankan population.The mean age of the study sample recruited is 58.5 years and this reflects the fact that cardiac patients are usually older. However, this study cohort is likely to be representative of Sri Lankan cardiac patients. Furthermore, with a large subject population of varying cardiovascular diagnoses, it provides an accurate representation of cardiac patients. Having been conducted in a group of patients who have direct implications of obesity on the causation and progression of their cardiovascular disease [3], and related co-morbidities, this study provides information which is important from the perspective of managing these types of patients.
A majority of the study population (55 %, n = 290) had higher than normal BMI values. This is perhaps to be expected considering their possible disease associations. Similarly, a high percentage (58 %, n = 306) had central obesity. This is in contrast to the 34 % of abdominally obese subject percentage noted in a Sri Lankan general population [19]. But in both studies, the prevalence of central obesity is higher among female participants compared to male counter part.
Body weight perception in this study group showed a clear tendency of under-estimation of their weight by the patients. This is evident by nearly half of the normal weight patients considering themselves to be ‘underweight’, 85 % of overweight reporting their weight as ‘normal’ or even ‘underweight’ and 85 % of obese patients failing to identify that they are ‘very overweight’. Similar weight misperceptions have been elicited in the Sri Lankan general population as well [19]. Yet for all that, the percentages of under-perception are higher in the current study sample. This under-perception is significant as these patients are in fact expected to have a better understanding of the concept of BMI and individual weight categories, with the information being targeted to them through the health care sector and the media in Sri Lanka. Although there are several awareness programmes on obesity and associated cardio-metabolic risks in both community and clinical settings, our findings showed that the expected inputs have perhaps failed to reach them adequately. Furthermore, the results indicate that higher the BMI, lesser are the percentages of patients who could accurately identify their weight category. More seriously, 23 % of those who were overweight and 11 % of overtly obese patients considered themselves to be ‘underweight’. Such misconceptions would not only prevent them from attempting to lose weight but will also put them at a higher risk for further increasing their weight as well.
In a previous study done in the sub-group of diabetic patients, significant distortions in self-perceived body weight have been found. In fact, this increased significantly with the increase in BMI weight status [12]. This is similar to the observations made in cardiac patients in the current study. Only 12 % of overweight and obese patients in a group of hypertensive patients correctly identified that they had higher than normal weight [13]. In the present group, only around 14 % of both overweight and obese patients managed to accurately state their weight status. These similarities observed between these patient groups, in contrast to the general population, could be expected, as the diseases themselves are most of the time inter-related or co-existent and there are similarities in the exposure of patients to health-related information.
Waist circumference is a more accurate indicator of the metabolic risk in South Asian populations [20]. Being a seminal criterion in defining the metabolic syndrome, it has a major impact on the development of metabolic diseases. Thus the patients with abdominal obesity, especially when they have already developed consequent metabolic or cardiovascular disease, should be aware of it. However the results indicate poor perception, with 62 % of abdominally obese males and 69 % of similar females reporting their weight status as ‘normal’ or ‘underweight’. Only one third of them considered themselves to have higher than normal weight. One could expect problems in them in a therapeutic attempt towards motivation towards weight loss in practices. This is in contrast to the Sri Lankan general population where two thirds of abdominally obese people accurately identified themselves to have an increased waist circumference [19].
The known medical complications of obesity include metabolic diseases such as diabetes, hypertension, hyperlipidaemia as well as ischaemic heart disease [3]. The selected sub-group of cardiac patients with co-morbid metabolic diseases showed an equal trend of body weight misperception with almost similar percentages in different self-perceived weight categories. This would lead one to the inevitable conclusion that weight misperception, especially under-perception when overweight, being a significant finding in the general cardiac patients as well as cardiac patients with co-morbid metabolic diseases. This is apparently more marked than misperceptions demonstrated in the general population from large-scale local studies [19]. Furthermore, this is quite important in view of the fact that this is the same patient population which is expected to be more vigilant about weight control. This misperception may be contributed to by several reasons. Unintentional weight loss is a symptom of diabetes. Furthermore, these patients may have already met health care personnel, including dieticians, from whom they may have received advice on diet and physical exercise, and may even have tried to comply with the suggestions to a certain extent. This could possibly have led to an impression formed within them that they have achieved some weight loss. However the negative impact of it is the failure to recognize that an optimal weight status has not been achieved yet. This subsequently results in under-perception of body weight. The results of this study bring out the notion that target populations should be given special attention in addressing weight status and clinicians should try to improve weight perception in these patients in order to enhance weight control practices.
Limitations
The present study did not specifically test for the understanding of the concept of central obesity in terms of perceived waist circumference. This could have been important to elucidate awareness of patients on this important clinical parameter. However, in a clinical perspective, weight loss practices that the patients are expected to follow would depend on the overall self-estimation of body weight. This study has not dealt with the association of self-perceived body weight with weight control practices in the cardiac patients and the effectiveness of such. Clearly, future studies would be needed in that respect.
Multiple logistic regression models were carried out for under-perception, correct perception and over perception of body weight. However clinically significant statistical associations were not elicited (Additional file 1). Probably, the existing knowledge on obesity and associated risk factors could be an associated factor. Further research is very important to identify the risk factors for the poor body weight perception in cardiac patients.