C.U.UBEYNARAYANA1, K.M.S. LOW1, A. MOH1, J. WANG1, S.C.LIM1, B.PANDIAN1, J. KHOO1, B. IRWAN1, Y.B. SOH1, S.F. WONG1
Khoo Teck Puat Hospital1
Obesity is a global public health problem for the past few decades. In this study, we aim to explore the sub-phenotypes of general obese population in Singapore. With a better understanding of the sub-phenotypes that exist, it may help risk stratification, resource allocation, and subpopulation target intervention.
A cross-sectional study was conducted on a large-scale population health cohort for residents aged > 40 years in the north region of Singapore (N=18,746). Exclusion criteria included BMI <23.5 (kg/m2), fasting plasma glucose ≥ 7 (mmol), or a history of diabetes medications. A total of 8,430 participants were randomly allocated into training (70%) and validation (30%) datasets. Clustering algorithm partition around medoids with Huang distance as dissimilarity measure was performed based on variables of age, METs-IR (a powerful surrogate for insulin resistance), SBP, gender, and ethnicity.
In the general obese population, two clusters were identified. Average silhouette widths for the subgroups were 0.62 and 0.58, respectively. Jaccard indices were above 0.9 for both subgroups, indicating stable clustering. The two obese clusters had distinct clinical profiles. Individuals in cluster 1 were relatively younger and metabolically healthy. Comparing to cluster 1, cluster 2 had higher lipid levels and higher blood pressure disproportional to age difference of 6.6 years. These characteristics were replicated in the validation dataset.
Results showed two sub-phenotypes in the general obese population: metabolically healthy and metabolically unhealthy, especially in disproportional high blood pressure, which may suggest different lifestyle management for a healthier life in the obese population.