The Korean Society for the Study of Obesity announced new guidelines for obesity treatment, breaking down the severity of overweight into three stages instead of two.
The KSSO announced the “2018 Clinical Practice Guidelines for Obesity” at an academic forum on Friday. The expert group presented the criteria for overweight based on body mass index (BMI), or a body weight divided by the square of body height.
The KSSO maintained the existing criteria for obesity at BMI of 25 kilograms per square meter or higher. However, the guidelines added Pre-Stage at 23-24.9 kg/㎡, and divided the severity into three -- Stage 1 at 25-29.9kg/㎡, Stage 2 at 30-34.9 kg/㎡, and Stage 3 at 35kg/㎡ or higher.
The obesity society came up with more detailed guidelines after surveying more than 20 million people who received the National Health Insurance Service’s health checkups and reflecting the risks of accompanying diseases in association with BMI and waist circumference.
Experts noted that the KSSO established a standard for Stage 3 Obesity (severely overweight) after confirming the relationship between BMI, waist circumference and the risk of accompanying diseases and death.
Analysis of Big Data of 20 million Korean adults showed that the cut-off point for the risk of having one of three diseases -- diabetes, hypertension, and dyslipidemia -- was 23 kg/㎡.
Even if BMI was normal at a pre-stage of obesity, males with more than 90-centimeter waist circumference and females with more than 85-centimeter waist circumference had similar risks of accompanying diseases as Stage 1 obese patients.
Stage 3 Obesity was set at BMI 35 35kg/㎡, based on the fact that an additional increase in BMI raises the incidence of associated diseases such as diabetes and hypertension.
The KSSO analyzed the risk of cerebrovascular disease and mortality in six groups (males over 80 centimeters of waist circumference, females over 75 centimeters, in 5 cm unit) to identify the risk of waist circumference gains.
The results showed that the risks of new myocardial infarction, ischemic stroke, and death of all causes (total mortality) were positively correlated with increases in waist circumference. The relationship between cardiovascular disease and waist circumference appeared more clearly on adjusted BMIs.
Even when the BMI was normal, an increase in waist circumference lifted up the total mortality rate sharply, suggesting that waist circumference may be a more predictive cursor than BMI for obesity-induced cardiovascular disease and death.
The KSSO also announced an interim result of a study on the cost of obesity treatment, which analyzed the NHIS’ sampled data on 500,000 people.
The study showed that obese patients spent a maximum of 508,781 won ($476) a year in additional medical expenses compared with people with a normal weight.
Stage 3 obese patients raised medical expenses by 14.3-50.1 percent compared with those with a normal weight. Based on waist circumference, those with a high figure spent 2.5-53.3 percent more money for medical care, indicating that abdominal obesity increased additional cost more.
“Physicians apply different cut-off points for abdominal obesity, depending on race or sex. It is significant we confirmed the abdominal obesity criteria reflecting the actual risk of Koreans,” said Lee Won-young, a professor of endocrinology and internal medicine at Kangbuk Samsung Hospital, who led the NHIS data-based research.
He went on to say, “Among Koreans, the cut-off point for risk of cardiovascular disease and mortality caused by abdominal obesity was lower than anticipated. So, waist circumference should be considered along with BMI in diagnosing overweight and preventing complications.”