Obesity is widely under diagnosed among South Asians due to the lack of awareness among health care professionals to adopt ethnicity-specific criteria for BMI and waist circumference (WC). This compilation of three studies conducted in the United States focuses on documenting trends in South Asian obesity and training physicians in modified BMI and WC criteria.
 

• Waist circumference
• Obesity
• South asians

Vasudevan DA, Klawans MR, Northrup TF, Stotts AL (2015) Diagnosis and Management of Obesity among South Asians – A Paradigm. J Family Med Community Health 2(7): 1056.

Obesity is an epidemic and a major contributor to the global health, economic, and financial burden related to chronic disease and disability. As global obesity rates increase, so do the challenges associated with disease identification and management in a diverse population using standard guidelines. Currently, obesity may be widely underdiagnosed among South Asians due to a lack of awareness among health care professionals on the universal adoption of ethnicity-specific modified criteria for BMI and waist circumference. The WHO has concluded that Asian individuals generally have a higher percentage of body fat than Caucasian individuals of the same age, sex, and BMI, as well as substantial risk factors for type-2 diabetes and cardiovascular disease at lower BMIs [1]. Studies that evaluated the cut-off for overweight/obese among Asians in relation to development of chronic disease revealed that a BMI between 23.0 and 25.0 kg/ m2 indicates that an Asian patient is overweight and that a BMI over 25.0 kg/m2 indicates that an Asian patient is obese [2-5]. Based on these findings, the WHO and International Diabetes Federation (IDF) have proposed modified criteria for classifying overweight/obesity among Asian population groups using lower BMI thresholds and waist circumference measurements. The IDF recommends using a cut-off of 80 cm (women)/90 cm (men) as the waist circumference to determine abdominal obesity in Asian patients. The WHO modified criteria suggested categories as follows: less than 18.5 kg/m2 underweight; 18.5–23 kg/m2 increasing but acceptable risk; 23–27.5 kg/m2 increased risk; and 27.5 kg/m2 or higher high risk [6]. While research in this area is limited due to inadequate ethnic representation, a few studies have shown that WHO-modified BMI and IDF waist circumference independently identified greater numbers of overweight/obese South Asian Indians [5]. These findings underscore that obesity is likely under-diagnosed among Asians using the standard WHO criteria for BMI and the NCEP ATPII guidelines for waist circumference. Therefore, risk prediction is not satisfactory, stressing the need to use modified overweight/ obesity definitions for Asians. These tailored criteria allow for more accurate risk assessment and disease identification and management, potentially preventing obesity and obesity-related disease progression. Appropriate Asian-specific thresholds must be employed to identify those who might benefit from counseling for moderate weight loss with lifestyle changes. Primary care providers play a pivotal role in obesity identification and prevention and it is crucial to raise awareness of appropriate criteria to increase the number of patients who receive obesity-related care, especially within patient groups for whom the recommended modified criteria are necessary. With the growing epidemic of obesity among this ethnic group, and associated risks of chronic disease and disability, it is a challenge to work towards early and accurate identification and management of obesity.

Study Methodology

We have conducted three studies on this subject. The initial study documented that modified criteria for BMI and waist circumference independently identified higher numbers of overweight/obese South Asian Indians. The second study assessed physician knowledge of appropriate diagnosis of obesity among South Asian Indians. The final study was an intervention to evaluate the efficacy of a training module on improving physician diagnosis and counseling of overweight/obese Asian patients.

Full study methods for Study One are published [5]. Briefly, the study used a cross-sectional design to compare the prevalence rates of obesity based on BMI and anthropometric measures using WHO/NCEP-ATP III/IDF standard and ethnicity-specific criteria among a migrant South Asian population. The WHO modified criteria used classified BMI of ≥ 23 kg/m2 as overweight and ≥ 25kg/m2 as obese and this was based on prior studies on this population group [1-4]. A total of 213 participants of South Asian descent from the Houston, TX area completed a questionnaire containing basic demographic information and self-reported history of diabetes, coronary artery disease, and hypercholesterolemia. Height, weight, waist/hip circumference, and blood pressure were measured. Chi-square tests were used to determine significant differences between groups.

Full study methods for Study Two are also published [7]. In short, a cross-sectional design was used to survey 183 physicians practicing in Houston, TX. Respondents reported on their knowledge on guidelines for obesity among South Asian Indians, frequency of measurement of obesity surrogate markers, self-reported competency in management of obesity, and readiness to seek training on obesity diagnosis among this ethnic group. Chi-square tests were used to determine significant differences between groups.

Study Three [8] evaluated the efficacy of a training module on improving physician diagnosis and counseling of overweight and obese Asian patients. Sixteen physicians received 1 hour of onsite training and other reminder resources describing the guidelines for the diagnosis of overweight/obesity among Asians, as well as weight counseling instruction. A total of 361 chart reviews of overweight/obese Asian patients were conducted for the 12 months before the training (n=198) and 3 months following the training (n=163). Physician race and clinic setting were outcome moderators. Logistic regression models and chi-square tests were used to analyze the resulting data.

Study One

The first study [5] documented that WHO modified BMI and IDF WC criteria independently identified higher numbers of overweight/obese participants; however when both criteria were used, 75% of patients were identified as overweight or obese. The IDF criteria for waist circumference identified 57.5 % of subjects (male=53%; female=63%; p<0.005), a significantly higher number among both genders as having central obesity compared to 25% (male=13%; female= 41%; p<0.005) by the NCEPATPIII criteria. Similarly, the modified waist-to-hip ratio (WHR) identified 75.4% of people as being overweight/obese compared to 19.9% using the standard WHR (p=<0.005).WHO-modified criteria identified a significantly higher proportion (67%) of the total cohort including both genders to be overweight/obese as compared to the WHO-standardized criteria (42%; p=<0.005; Males: 71% Vs 42%; Females: 61% Vs 42%; p<0.005) (Table 1).

Table 1: Distribution of BMI and WC by gender.

Study Two

Findings from the second study [7] showed that 65% of physicians agreed that obesity is a growing problem among South Asian Indians. About 68% of the physicians estimated that more than half of their patients were overweight/obese, but only 9% reported routine use of waist circumference measurements to assess abdominal obesity. Only 29% of all physicians were aware of the WHO recommended modified ethnicity-specific, cut-off for BMI with a higher percent of South Asian Indian Providers (SAIP) (39%) reporting awareness of the issue compared to 25% of Other Providers (OP) (p=0.079). More than 75% of the practicing physicians were unaware of the actual numerical values for the modified WHO recommended ethnicity-specific BMI cut off. More than 75% of practicing physicians were unaware of the actual numerical values for the modified WHO recommended ethnicityspecific BMI cut off and 41% were aware of the IDF criteria for waist circumference (Table 2).

Table 2: Physician Knowledge of Ethnicity-Specific Cut-off Points for Obesity Among South Asian Indians.

The percent of physicians who reported adequate training to manage obesity specifically among South Asian Indians was low for all groups (22%); but marginally better among SAIP (32%) compared to OP (20%; p=0.089). Nearly half of all physicians reported that they counsel patients with ethnicity-specific dietary changes and physical activity; More than 75% reported readiness to obtain training on guidelines for South Asian Indians (Table 3).

Table 3:Comparison of physician self-measured degree of competence in treating South Asian Indians across ethnicity and training.

Study Three

The findings from the third study showed that post training levels of diagnosis were significantly higher than pre-training levels across all physicians, 26.8% and 45.1% of patients were accurately diagnosed as overweight or obese before and after the training, respectively (p<0.05; Figure 1).

Figure 1 Percent of Correctly Diagnosed and Weight Counseled Patients.

The odds of a physician correctly diagnosing Asian patients as overweight or obese were 102% higher at post-training after accounting for nesting of patients within physicians. Similarly, weight counseling was higher (65.0%) following training compared to pre-training levels (43.9%) but failed to reach significance (p=0.06).

Asians in general and South Asian Indians in particular, are among the fastest growing immigrant groups in the Western world and are at high risk for developing obesity, diabetes, and cardiovascular heart disease at lower BMI and waist circumference cut-offs compared to other ethnic groups [1- 4]. Research shows that South Asian Indians have one of the highest global risks of all ethnic groups for metabolic syndrome and its associated morbidities [9]. The initial study results show a statistically significant difference in rates of obesity with the WHO-modified BMI criteria identifying 67% of the population as overweight/obese. This supported our hypothesis that standard WHO guidelines for obesity diagnosis are inadequate among South Asian Indians given their high prevalence rates of diabetes, metabolic syndrome and early CAD at lower anthropometric measures. The current recommended cut-offs for BMI by WHO are largely based on the morbidity and mortality data from the white Caucasian population and may not be applicable across all ethnic groups. A recent study in the USA done by Misra et al. on the prevalence of diabetes, metabolic syndrome and cardiovascular risk factors in US Asian Indians (N=1038) showed that the mean BMI was 25.4 ± 3.7, and there was a significant difference with 38% and 11% being classified as overweight and obese using standard criteria whereas 25% and 49.8% were classified as overweight and obese using modified WHO criteria [8]. Our study [5] reproduced these findings, with the mean BMI being 24.5 ± 3.6 and thus 58% of the patients (n=213) were classified as normal weight using the standard WHO criteria. Abdominal obesity assessed by measuring waist circumference and waist-tohip circumference ratio (WHR) is increasingly being recognized as an important cardiovascular risk factor [1]. The currently recommended cut-off for waist circumference by NCEP ATPIII may not be applicable to all ethnic groups and hence IDF has recommended using lower cut-off points for waist circumference to diagnose abdominal obesity and as an inclusion criteria for metabolic syndrome among the South Asian ethnic group and this has been supported by the American Heart Association. A recent national study of Asian Indians in the US showed the age-adjusted prevalence of abdominal obesity to be 12.8 % and 56.4% for men and 36.3% and 68% for women using the NCEP ATPIII and IDF criteria respectively [9]. Our study [5] showed statistically significant higher rates of abdominal obesity using the IDF criteria (males= 53%; females=63%; p<0.005) compared to the NCEP ATPIII criteria (males=13%; females=41%). It also showed that using the combined WHO-modified criteria for BMI and/or IDF for WC group had significantly higher rates of identifying overweight/obese people in comparison to the standard WHO BMI, NCEP ATPIII waist circumference and other combination criteria.

Obesity is one of the most important risk factors included in the metabolic syndrome, and studies including ours indicate the under diagnosis of overweight/obesity among this ethnic group is common. Study one showed that physicians in general were aware of the progressive nature of obesity among SAI patients and acknowledged that abdominal obesity was a risk factor for CVD in this group. The study, similar to other limited studies in this field, demonstrated a low rate of awareness (20%) on the specific numerical cut-off for modified ethnicity-specific BMI; with no significant gender or ethnicity difference. The Shape of the Nations survey showed that in North America 37% of PCP’s knew the threshold WC for men (p<.05), and only 8% for women [10]. It is indeed concerning that greater than half of the surveyed physicians were unaware of the appropriate current guidelines for obesity diagnosis among SAI patients. Our study showed that physicians were aware of the morbidity associated with abdominal circumference, but less than 10% measured waist circumference as a surrogate marker indicating a need for emphasizing the importance of visceral obesity and its early identification in this ethnic group. A study done by Schuster on implementation of obesity guidelines in a primary care setting, among physicians with enhanced educational intervention and regular interventions for obesity, found that there were more significant weight loss and cardiovascular morbidity improvements among patients in the enhanced physician interventions groups [11]. Although only 22% of physicians reported adequate training to manage obesity among SAI patients specifically, more than 75% of them were willing to seek training on ethnicity-specific management of obesity.

To better care for the health of a growing Asian population there is an increasing need for physicians to identify and counsel Asian patients who are overweight or obese to reduce the physical, behavioral and economic burden that accompanies obesity progression. Efficacious physician training on race-specific guidelines for diagnosing and managing obesity is a critical first step in this effort. Our work demonstrated that training physicians on race-specific diagnostic guidelines for obesity and weight counseling strategies led to significant changes in physicians’ rates of diagnosis. Further, study three demonstrated that using race-specific weight counseling strategies provided meaningful changes for some groups of physicians providing weight counseling. Following instruction, accurate diagnosis and physician-provided weight counseling were approximately 20% higher. The significant change in physician diagnosis was strongest for non-Asian physicians and physicians in academic settings. Brief physician training may be sufficient to significantly increase rates of accurate physician diagnosis among Asian populations.

With the rapidly growing Asian population in the western world, and a lack of physician knowledge and awareness on obesity management among Asian patients, there is a need for physicians to be educated and trained on appropriately identifying overweight/obese Asian patients and providing counseling and resources to ensure successful patient weight loss and maintenance. These studies demonstrated an under diagnosis of overweight/obese among Asians using standard guidelines and an effective approach by which to increase physician awareness and action toward meeting these goals.

The authors would like to thank the clinic staff and physicians at the UTPB Family Medicine Clinic for their support in completing these three studies.

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