Body Mass Index and Weight Distribution

It has been accepted for many years that being overweight or obese, as indicated by a body mass index (BMI) of 25 or over for the former and 30 or over for the latter, is associated with impairment of long term health and prognosis. The World Health Organisation (WHO) has indicated that, in Caucasians, waist measurements of 94cm or more in men, and 80cm or more in women have similar adverse effects on health, with increased risks at 102 cm or more in men and 88 cm in women. The role of waist-hip ratio (W/H) and whether it represents a better index than waist (W) measurement alone is being debated; many papers favour waist measurement alone. But two papers in 2005 discussing 27,098 subjects, 12,461 of whom had myocardial infarction and 14,637 controls, come down firmly in favour of W/H and were followed by a Lancet Editorial entitled ‘Farewell to Body Mass Index?’ Life assurance companies at medical examination usually request height and weight measurements (and therefore BMI). Most ask for waist measurements and a few hip measurements in addition (and therefore W/H). The authors have reviewed the data in 816 consecutive subjects for life assurance examination in whom BMIs, Ws and W/Hs were all recorded. In these the evidence supports the use of W as the best indicator of risk in men (634 cases), but not in the relatively small number of women (182 cases) in whom H appeared better. We believe that BMI, W and W/H should be recorded in every subject at life assurance examination so that the insurance companies in the long term will be able to reach valid conclusions about their individual and collective value </jats:p

Impact of Bariatric Surgical Intervention on Peripheral Blood Neutrophil (PBN) Function in Obesity.

AIM The aim of this study was to investigate the impact of weight loss following gastric band surgery on multiple measures of peripheral blood neutrophil (PBN) function. MATERIAL AND METHODS Twenty-three obese patients undergoing gastric band surgery were recruited to a longitudinal intervention study, alongside non-obese, healthy gender- and age-matched controls. Eighteen pairs of patients and controls completed all stages of the study. PBNs were isolated by density centrifugation and a comprehensive analysis of PBN function was undertaken at various stages of the patients' bariatric surgical care pathway. RESULTS Obese patients exhibited exaggerated PBN activity in response to various stimuli, characterised by higher reactive oxygen species (ROS) generation (n = 18, p < 0.001) and release of pro-inflammatory cytokines (n = 10, p < 0.05) and lower PBN extracellular trap (NET) formation (n = 18, p < 0.01). PBN chemotactic accuracy was also impaired prior to surgery (n = 18, p < 0.01). Weight loss was associated with normalised NET production and lower ROS production and cytokine release relative to healthy controls. However, chemotactic accuracy remained impaired in patients. CONCLUSIONS Weight loss following gastric band surgery was associated with a decrease in the pro-inflammatory activities of peripheral blood neutrophils (PBNs). A hyper-inflammatory PBN phenotype, involving excess ROS and cytokine release, reduced NET formation and chemotaxis, may lead to a reduced ability to eliminate infection, alongside inflammation-mediated tissue damage in obese individuals