Prevalence of normal weight obesity and its associated cardio-metabolic risk factors - Results from the baseline data of the Kerala Diabetes Prevention Program (KDPP)

BACKGROUND: Cardiometabolic disorders are frequently observed among those who have obesity as measured by body mass index (BMI). However, there is limited data available on the cardiometabolic profile of those who are non-obese by BMI but with a high body fat percentage (BFP), a phenotype frequently observed in the Indian population. We examined the prevalence of individuals with normal weight obesity (NWO) and the cardiometabolic profile of NWO individuals at high risk for type 2 diabetes(T2D) in a south Asian population. MATERIAL AND METHODS: In the Kerala Diabetes Prevention Program, individuals aged between 30 to 60 years were screened using the Indian Diabetes Risk Score(IDRS) in 60 rural communities in the Indian state of Kerala. We used data from the baseline survey of this trial for this analysis which included 1147 eligible high diabetes risk individuals(IDRS >60). NWO was defined as BMI within the normal range and a high BFP (as per Asia-pacific ethnicity based cut-off); Non-obese (NO) as normal BMI and BFP and overtly obese (OB) as BMI ≥25 kg/m2 irrespective of the BFP. Data on demographic, clinical and biochemical characteristics were collected using standardized questionnaires and protocols. Body fat percentage was assessed using TANITA body composition analyser (model SC330), based on bioelectrical impedance. RESULTS: The mean age of participants was 47.3 ± 7.5 years and 46% were women. The proportion with NWO was 32% (n = 364; 95% CI: 29.1 to 34.5%), NO was 17% (n = 200) and OB was 51% (n = 583). Among those with NWO, 19.7% had T2D, compared to 18.7% of those who were OB (p value = 0.45) and 8% with NO (p value = 0.003). Among those with NWO, mean systolic and diastolic blood pressure were 129 ± 20; 78 ± 12 mmHg, compared to 127 ± 17; 78±11 mmHg among those with OB (p value = 0.12;0.94) and 120 ± 16; 71±10 mmHg among with NO (p value<0.001; 0.001), respectively. A similar pattern of association was observed for LDL cholesterol and triglycerides. After adjusting for other risk factors, the odds of having diabetes (OR:2.72[95% CI:1.46-5.08]) and dyslipidemia (2.37[1.55-3.64]) was significantly more in individuals with NWO as compared to non-obese individuals. CONCLUSIONS: Almost one-third of this South Asian population, at high risk for T2D, had normal weight obesity. The significantly higher cardiometabolic risk associated with increased adiposity even in lower BMI individuals has important implications for recognition in clinical practice

Facilitated antigen uptake and timed exposure to TLR ligands dictate the antigen-presenting potential of plasmacytoid DCs

Subsets of antigen-presenting cDCs have a differential capacity to present exogenous and endogenous protein antigens to CD4(+) and/or CD8(+) T lymphocytes, depending on expression of antigen-uptake receptors, processing machinery, and microbial instruction. pDCs are also capable of antigen presentation, but the conditions under which they do this have not been systematically addressed. Highly purified cDCs and pDCs were exposed to exogenous, soluble OVA peptide or whole protein. Alternatively, they were made to express cytoplasmic or endosomal OVA by retroviral transduction or by infection with influenza virus containing OVA epitopes. Like cDCs, pDCs expressed the MHC I processing machinery and could present endogenous or cross-present exogenous OVA to CD8(+) T cells, provided they had been stimulated by CpG motif TLR9 ligands or by influenza. Unlike cDCs, the cross-priming activity of pDCs was enhanced, not decreased, by simultaneous TLR stimulation. Processing and presentation of exogenous OVA to CD4(+) T cells required TLR9 ligation prior to antigen encounter and addition of OVA-specific Igs. These stimuli up-regulated critical MHC II processing machinery and enhanced routing to acidic endosomal organelles in a Fc gamma RII-dependent manner. Endogenous antigen was not presented to CD4(+) T cells when expressed in the cytoplasm of pDCs by retrovirus or contained in influenza, unless an Ii-chain-derived endosomal routing signal was present. Thus, timing of TLR ligation and facilitated antigen uptake dictate the potential of pDCs to present endogenous or exogenous antigen by influencing endosomal traffic and antigen-processing machinery. J. Leukoc. Biol. 90: 1177-1190; 2011