Ji-Hee Haam, Bom Taeck Kim, Eun Mi Kim, Hyuktae Kwon, Jee-Hyun Kang, Jung Hwan Park, Kyoung-Kon Kim, Sang Youl Rhee, Yang-Hyun Kim, Ki Young Lee. J Obes Metab Syndr 2023;32:121-9. https://doi.org/10.7570/jomes23031

Ga Eun Nam, Yang-Hyun Kim, Kyungdo Han, Jin-Hyung Jung, Eun-Jung Rhee, Seong-Su Lee, Dae Jung Kim, Kwan-Woo Lee, Won-Young Lee, on behalf of the Taskforce Team of the Obesity Fact Sheet of the Korean Society for the Study of Obesity. J Obes Metab Syndr 2020;29:124-32. https://doi.org/10.7570/jomes20058

Background: Waist circumference (WC) is an index of abdominal obesity and associated with co-morbidities and mortality. Higher WC is positively associated with increased mortality; therefore, we examined the relationship between WC and mortality in Korean populations with the interaction of body mass index (BMI) and WC for mortality. Methods: A total of 23,263,878 subjects (men = 11,813,850 and women = 11,450,028) who were older than 20 years and underwent the National Health Insurance Service health checkup were included. WC was divided into six categories by 5 cm increments and level 3 (85–90 cm in men and 80–85 cm in women) was referenced. Multivariable Cox proportional hazard models were used to obtain the hazard ratios (HRs) and 95% confidence intervals for all-cause mortality according to the six levels of WC. Results: WC in 5 cm increments showed a positively increased all-cause mortality after adjusting for all covariates including BMI. Men showed higher HRs for mortality than women as WC increased, and the HRs were higher in the lower WC levels, but lower in the higher WC levels among the subjects aged 65–85 years than subjects aged 40–65 years. Even in subjects with normal weight and overweight, increased WC (levels 4, 5, and 6) showed increased HRs for mortality (HRs = 1.156, 1.412, and 1.614 in normal BMI and 1.145, 1.401, and 1.909 in overweight, respectively). Conclusion: There was a linear association between WC and all-cause mortality across all BMI categories even in the subjects with normal or overweight BMI. Physicians should check WC routinely even in the subjects with normal weight or overweight.

With the Euro-Qol-5 dimension (EQ-5D) system, we investigated the relationship between the number of remaining teeth and QoL using data from the Korean National Health and Nutrition Examination Survey (KNHANES), 2010–2012. A total of 17,417 participants, more than 19 years old, were finally included in this study (men = 7394 and women = 10,023). Through this study, we have discovered that the remaining teeth affect overall health and that the fewer number of them may indicate a lower quality of life, as well. The quality of life according to the number of remaining teeth was assessed among Koreans using the Euro-Qol-5 dimension (EQ-5D) system. The Euro-Qol-5 dimension (EQ-5D) system was used to measure the health-related QoL. Its five dimensions included mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The respondents were asked to choose one of the followings: G 1, no problems; G 2, some problems; and G 3, problematic, to best describe their health status for the five dimensions. Then, we assigned low QoL to G2 + G3 and high QoL to G1. We used age, gender, economic income, educational level, residence, and marital status for the demographic variables and, drinking, smoking, exercise, BMI, and metabolic syndrome for health behaviors. Multiple logistic regression analysis was performed to examine the odds ratios (ORs) and confidence intervals (CIs) for the high QoL (G1) on the five categories of EQ-5D according to the number of remaining teeth. On the basis of the 0–15 remaining teeth group, we drew a comparison of the QoL between the 16–20 and 21–28 remaining teeth groups. Subjects with 21–28 remaining teeth had higher QoL scores and had higher ORs of high QoL, especially for mobility (OR = 1.256, 95% CI = 1.056–1.495), self-care (OR = 1.441, 95% CI = 1.096–1.894), and usual activities (OR = 1.241, 95% CI = 1.022–1.508, respectively), than those with 0–15 remaining teeth after adjusting for age, sex, body mass index, smoking, drinking, exercise, income, education, and metabolic syndrome. ORs from the high QoL had the tendency to increase as the number of remaining teeth increased (all p for trend < 0.05). However, there was no relationship between the number of remaining teeth and QoL in the pain/discomfort and anxiety/depression dimensions. The number of remaining teeth was associated with QoL, and subjects who had more teeth obtained higher QoL scores. The subjects in the high QoL group were especially associated with the components of EQ-5D such as mobility, self-care, and daily living.

We aimed to investigate how body weight fluctuation affects the risk of developing type 2 diabetes by conducting a nationwide cohort study. A total of 3,855,884 participants from the National Health Insurance System health check-up data from 2012 were included in this study, and follow-up continued until 2016. Body weight was measured at least thrice between 2009 and 2012. Body weight variability (BWV) was estimated using average successive variability (ASV) indices. Cox proportional hazards regression models were used to evaluate the association of BWV with the risk of type 2 diabetes using hazard ratios (HRs) and 95% confidence intervals (CIs). Body weight fluctuation was associated with a higher risk of incident diabetes after adjustment for confounders (HR 1.10, 95% CI 1.07, 1.12 in the highest BWV quartile compared to the lowest). Regardless of the weight change status, the highest ASV quartile of BWV increased the risk for diabetes. Even subjects with a normal glucose tolerance status and those aged under 65 years had a higher risk of diabetes if their body weight highly fluctuated during the follow-up years. Our results suggest that body weight variability is an independent risk factor for diabetes. It is important to pay attention to frequent body weight fluctuations.

OBJECTIVE: There is a controversy over the association between obesity and end-stage renal disease (ESRD) in people with or without type 2 diabetes; therefore, we examined the effect of BMI on the risk of ESRD according to glycemic status in the Korean population. RESEARCH DESIGN AND METHODS: The study monitored 9,969,848 participants who underwent a National Health Insurance Service health checkup in 2009 from baseline to the date of diagnosis of ESRD during a follow-up period of ∼8.2 years. Obesity was categorized by World Health Organization recommendations for Asian populations, and glycemic status was categorized into the following five groups: normal, impaired fasting glucose (IFG), newly diagnosed diabetes, diabetes <5 years, and diabetes ≥5 years. RESULTS: Underweight was associated with a higher risk of ESRD in all participants after adjustment for all covariates. In the groups with IFG, newly diagnosed type 2 diabetes, diabetes duration <5 years, and diabetes ≥5 years, the hazard ratio (HR) of the underweight group increased with worsening glycemic status (HR 1.431 for IFG, 2.114 for newly diagnosed diabetes, 4.351 for diabetes <5 years, and 6.397 for diabetes ≥5 years), using normal weight with normal fasting glucose as a reference. The adjusted HRs for ESRD were also the highest in the sustained underweight group regardless of the presence of type 2 diabetes (HR 1.606 for nondiabetes and 2.14 for diabetes). CONCLUSIONS: Underweight showed more increased HR of ESRD according to glycemic status and diabetes duration in the Korean population. These associations also persisted in the group with sustained BMI during the study period.