Body Mass Index and Obesity : Tailoring “cut-off” for an Asian Indian Male Population

Background

Obesity/overweight is a recognized risk factor for a host of disorders. The disease risk stratification is commonly based on the Quetelets Index (Body Mass Index- BMI), a surrogate measure of fatness. The currently used BMI cut-offs to classify people as overweight or obese in Armed Forces have been defined in studies on Caucasian populations. However, because of differences in body structure and composition in different ethnic, socioeconomic, cultural and regional groups the correspondence between BMI and body fat content varies between populations. We conducted this pilot study in the Indian Navy to define BMI cut-offs for overweight and obesity using body fat content derived from Skin Fold Thickness as the standard.

Material and Methods

The study was conducted on 121 volunteers from a naval hospital staff in the age range of 18 to 47 years. The mean age, height, weight, BMI, body fat in the study group was 26.73 years (± 5.5098), 168.56 cm (± 6.1034), 65.92 Kg (± 10.2746), 23.17 Kg/m² (± 3.0265) and 19.91% (± 4.831) respectively.

Results

The prevalence of overweight/obesity was 20.66% by BMI and 47.11% by body fat content. Receiver operating characteristic (ROC) curve analysis defined a BMI of 23.85 kg/m² as the cut off for overweight with a sensitivity of 70.2% (95% CI 56.6 – 81.6) and 87.5% specificity (95% CI 76.8-94.4) and a BMI of 24.38 kg/m²with 90% sensitivity (95% CI 68.3-98.5) and 81.2% specificity (95% CI 72.2-88.3) for obesity.

Conclusion

The results of our study suggest lower BMI cut offs for overweight and obesity in Indian populations than those recommended by WHO.Key Words: Body Mass Index, Body fat content, Skin fold thickness     

Bioequivalence study of two capsule formulations containing diacerein 50 mg in healthy human subjects

This study presents the results of a two-way, two-period, two-treatment crossover investigation in 12 healthy Indian male subjects to assess the bioequivalence of two oral formulations containing 50 mg of diacerein (CAS 13739-02-1). Both formulations were administered orally as a single dose separated by a one-week washout period. The content of diacerein in plasma was determined by a validated HPLC method with UV detection. The formulations were compared using the parameters area under the plasma concentration-time curve (AUC(0-t)), area under the plasma concentration-time curve from zero to infinity (AUC(0-infinity)), peak plasma concentration (Cmax), and time to reach peak plasma concentration (tmax). The results of this study indicated that there were no statistically significant differences between the logarithmically transformed AUC(0-infinity) and Cmax, values of the two preparations. The 90% confidence interval for the ratio of the logarithmically transformed AUC(0-t), AUC(0-infinity) and Cmax were within the bioequivalence limit of 0.8-1.25 and the relative bioavailability of the test formulation was 96.63% of that of the reference formulation. Thus, these findings clearly indicate that the two formulations are bioequivalent in terms of rate and extent of drug absorption.     

Effect of common polymorphisms of the farnesoid X receptor and bile acid transporters on the pharmacokinetics of ursodeoxycholic acid

Ursodeoxycholic acid (UDCA), a natural, dihydroxy bile acid, promotes gallstone dissolution and has been attributed with several other beneficial effects. The farnesoid X receptor (FXR) may influence the pharmacokinetics of UDCA by modulating the expression of bile acid transporters. This exploratory study examined whether common functional polymorphisms in FXR and in bile acid transporter genes affect the pharmacokinetics of exogenous UDCA. Polymorphisms in genes for transporters involved in bile acid transport, solute carrier organic anion 1B1 (SLCO1B1) 388A>G and 521T>C, solute carrier 10A1 (SLC10A1) 800 C>T and ATP‐binding cassette B11 (ABCB11) 1331T>C, and the FXR ‐1G>T polymorphism were genotyped in 26 male Chinese subjects who ingested single oral 500‐mg doses of UDCA. Plasma concentrations of UDCA and its major conjugate metabolite glycoursodeoxycholic acid (GUDCA) were determined. The mean systemic exposure of UDCA was higher in the five subjects with one copy of the FXR ‐1G>T variant allele than in those homozygous for the wild‐type allele (n = 21) (AUC_0–24 h: 38.5 ± 28.2 vs. 20.9 ± 8.0 μg h/mL, P = 0.021), but this difference appeared mainly due to one outlier with the ‐1GT genotype and elevated baseline and post‐treatment UDCA concentrations. After excluding the outlier, body weight was the only factor associated with plasma concentrations of UDCA and there were no significant associations with the other polymorphisms examined. None of the polymorphisms affected the pharmacokinetics of GUDCA. This study showed that the common polymorphisms in bile acid transporters had no significant effect on the pharmacokinetics of exogenous UDCA but an effect of the FXR polymorphism cannot be excluded.     

博莱霉素致肺纤维化大鼠肺组织表面活性物质蛋白A B C mRNA的表达

目的观察博莱霉素致肺纤维化大鼠肺组织表面活性物质蛋白（ＳＰ）Ａ、Ｂ、ＣｍＲＮＡ的表达。方法气管内灌注博莱霉素Ａ５，复制肺纤维化模型，分别于３、７、１４和２８天处死动物，提取肺组织总ＲＮＡ，进行Ｎｏｒｔｈｅｒｎ杂交。结果肺纤维化大鼠肺泡Ⅱ型上皮细胞数量增加。灌注博莱霉素后第３天ＳＰＡ、ＳＰＢ及ＳＰＣｍＲＮＡ的表达即开始下降，７天时降至最低点，而后于１４天时开始回升，至２８天时上升最明显。但仍低于正常。结论博莱霉素致纤维化大鼠肺组织ＳＰＡ、ＳＰＢ及ＳＰＣｍＲＮＡ的表达减低。肺泡Ⅱ型上皮细胞功能的改变可能参与肺纤维化的发病过程。     

Clinical isolates of Staphylococcus aureus have osteolytic surface proteins and a proportion of the population have antibodies that block this activity: is this of prognostic significance?

Staphylococcus aureus is directly implicated in the bone destruction associated with infected orthopaedic implants and bacterial arthritis. The Oxford (laboratory) strain of this organism has surface-associated proteins (SAPs) which have potent osteolytic activity. In this study, we have examined the osteolytic activity of SAPs from clinical isolates and also investigated the role of the humoral immune response to such proteins. Nine patients with infected orthopaedic prostheses or infective arthritis, and six volunteers not suffering from overt S. aureus infection, were examined. The sera from 5/9 patients and 4/6 volunteers were able to neutralize the osteolytic activity of the SAPs. The SAPs were extracted from four clinical isolates and were found to have osteolytic activity, but with a wide range of efficacies and potencies. All four patients from whom the clinical isolates were obtained had serum IgG antibodies to the surface proteins from their autologous isolates as determined by ELISA. In conclusion, clinical isolates of S. aureus contain osteolytic SAPs which may be responsible for bone destruction. Apparently disease-free individuals and patients have antibodies able to block this activity. However, since the capacity of patients' sera to neutralize the activity of the SAPs derived from their own S. aureus isolate was not investigated, it is unclear whether these findings are of prognostic value.      

Enhanced co-stimulatory ability of synovial fluid accessory cells in rheumatoid arthritis

We have established in vitro assays that allow the examination of co- stimulatory function of rheumatoid arthritis (RA) antigen-presenting cells (APC). Synovial fluid (SF) and peripheral blood (PB) APC co- stimulatory ability was compared in the activation of peptide-specific human T-cell clones. T-cell receptor (TCR) stimulation by peptide or anti-CD3 antibody allowed the direct comparison of SF and PB APC co- stimulatory activity, separately from their ability to process antigen. SF APC from 15 RA patients consistently enhanced T-cell proliferation when compared to their PB counterparts. Moreover, increasing the numbers of PB APC present resulted in only a minor increase in T-cell proliferation, failing to achieve levels stimulated by SF APC. We propose that the enhanced co-stimulatory function of synovial APC may be a significant factor in the persistence of local immune responses in RA.      

Hematopoietic supportive functions of mouse bone marrow and fetal liver microenvironment: dissection of granulocyte, B-lymphocyte, and hematopoietic progenitor support at the stroma cell clone level

We dissected the functions of the microenvironment of bone marrow (BM) and fetal liver (FL) at the cellular level by cloning individual stromal calls and characterizing their phenotypical and functional features. Stromal cell clones derived from FL are large in size (mean forward light scatter intensity [mFSC] of 450), express the surface antigen Thy-1 but not Sca-1 and 6 out of 6 are able to differentiate into fat accumulating adipocytes. BM derived stromal cell clones are either small (mFSC of 250) or large (mFSC of 450), express Sca-1 but not Thy-1 and only 2 out of 7 differentiate towards adipocytes. Heterogeneity in terms of vascular adhesion molecule-1, intracellular adhesion molecule-1 and heat stable antigen expression was found among the different cell clones. Functional assays using long- and short-term cocultures of stromal and hematopoietic calls revealed: (1) the capacity of 8 out of 12 stromal cell clones to support the expansion of primitive hematopoietic progenitors (colony forming unit spleen day 12) more than 10 weeks. Fat accumulation but not expression of stem cell factor by stromal cells did correlate with this supportive function. (2) Better support of granulocyte maturation and proliferation by BM- compared to FL-derived stromal cell clones. However, stromal cell clones from both organs expressed macrophage-colony stimulating factor. (3) The ability of 4 out of 12 stromal cell clones (derived from both, FL and BM) to support the expansion of Interleukin-7 dependent pre-B cells from the BM. Pre-B cell growth stimulating factor was not restricted to supporters. (4) Mutual exclusiveness of myeloid and lymphoid support in that a given stromal cell clone supported either pre B-cell or granulocyte expansion. Experiments comparing the support of BM- and FL-derived hematopoietic progenitors showed identical responses of late (B220+/c-kit-) but strikingly different responses of early (B220+/c-kit+) pre-B cells, revealing different proliferation requirements for FL- versus BM- derived early pre-B cells in vitro.