Exposure to high sugar diet (HSD) is an experimental model of insulin resistance (IR) and type 2 diabetes (T2D) in mammals and insects. In Drosophila, HSD-induced IR delays emergence of pupae from larvae and eclosion of imago from pupae. Understanding of mechanisms of IR/T2D is essential for refining T2D prevention and treatment strategies. Dysregulation of tryptophan (Trp)-kynurenine (Kyn) pathway was suggested as one of the mechanisms of IR/T2D development. Rate-limiting enzyme of Trp-Kyn pathway in Drosophila is Trp 2,3-dioxygenase (TDO), an evolutionary conserved ortholog of human TDO. We previously reported attenuation of HSD-induced IR in vermilion mutants with inactive TDO. Conversion of Trp to Kyn is regulated not only by TDO activity but by intracellular Trp transport via ATP-binding cassette (ABC) transporter encoded by white gene in Drosophila. In order to evaluate the possible impact of deficient intracellular Trp transport on the inducement of IR by HSD, we compared the effect of HSD on pre-imago development in wild type flies, Canton-Special (C-S), and C-S flies containing white gene, white (C-S). Presence of white gene attenuated (by 50%) HSD-induced delay of pupae emergence from larvae and female and male imago eclosion from pupae. Present study together with our earlier report reveals that both decreased TDO activity (due to vermilion gene mutation) or deficient Trp transport into cell without affecting TDO levels (due to white gene mutation) attenuate HSD-induced development of IR in Drosophila model of T2D. Our data provide further support for hypothesis that dysregulation of Trp-Kyn pathway is one of the pathophysiological mechanisms and potential target for early diagnosis, prevention and treatment of IR/T2D.
Bariatric surgery has emerged as a viable treatment option in morbidly obese individuals with type 2 diabetes. Concomitant with societal lifestyle changes and the increased emphasis on achieving metabolic targets, there has been a rise in the number of patients with type 1 diabetes (T1DM) who are overweight and obese. Preliminary experience based on a limited number of observational reports points to substantial weight loss and amelioration of comorbid conditions such as blood pressure and dyslipidemia in patients with T1DM who undergo weight loss surgery. However, there is little evidence to suggest significant improvement in glycemic control and lowering of glycosylated hemoglobin, and bariatric surgical procedures do not necessarily lead to enhanced diabetes management. and improved quality of life. The potential possibility of micronutrient deficiency, weight regain, and psychobehavioral issues post-bariatric surgery also exists. An individualized evaluation of the risks and benefits should be considered, using a a multidisciplinary team approach with expertise in patient selection, surgical technique, and follow-up. A crucial component is the availability of a diabetes care specialist or endocrinologist experienced in intensive, tailored, modifiable insulin regimens who maintains close and careful monitoring during all phases of management. Reliable data from a prospective, longitudinal perspective is required to provide guidelines for clinicians and informed choices for obese patients with T1DM who are contemplating bariatric surgery.
The aim of the study was to examine the association of different measures of obesity (body mass index or BMI, waist circumference or WC, waist to hip ratio or WHR and waist height ratio or WHtR) with coronary heart disease (CHD) in a Bangladeshi population. The study included 189 hospitalized CHD cases (133 men and 52 women) and 201 controls (137 men and 68 women). Logistic regression was done to assess the associations between obesity and CHD. The mean age was 53.1 ± 8.3 for men and 51.9 ± 8.4 for women. After adjustment for confounders the odds ratio (OR) of CHD for men was 1.69 (95% CI, 1.24-2.32), 1.94 (95% CI 1.40-2.70), and 1.32 (95% CI, 1.01-2.16) per 1 standard deviation (SD) increase in BMI, WC, and WHtR respectively. The OR for women was 2.64 (CI, 1.61-4.34), 1.82 (95% CI 1.12-2.95), 2.32 (95% CI, 1.36-3.96), and 1.94 (95% CI, 1.23-3.07) per 1 SD increase in BMI, WC, WHtR and WHR respectively. Since both total obesity and abdominal adiposity were associated with development of CHD and since measurement of WC and BMI are inexpensive, both should be included in the clinical setting for CHD risk assessment for this group of population.
Exposure to high sugar diet (HSD) serves as an experimental model of insulin resistance (IR) and type 2 diabetes (T2D) in mammals and insects. Peripheral IR induced by HSD delays emergence of pupae from larvae and decreases body weight of Drosophila imago. Understanding of mechanisms of IR/T2D is essential for refining T2D prevention and treatment strategies. Dysregulation of tryptophan (TRP) - kynurenine (KYN) pathway was suggested as one of the mechanisms of IR development. Rate-limiting enzyme of TRP - KYN pathway in Drosophila is TRP 2,3-dioxygenase (TDO), an evolutionary conserved ortholog of human TDO. In insects TDO is encoded by vermilion gene. TDO is not active in vermilion mutants. In order to evaluate the possible impact of deficient formation of KYN from TRP on the inducement of IR by HSD, we compared the effect of HSD in wild type (Oregon) and vermilion mutants of Drosophila melanogaster by assessing the time of white pupae emergence from larva and body weight of imago. Delay of emergence of pupae from larvae induced by high sucrose diet was less pronounced in vermilion (1.4 days) than in Oregon flies (3.3 days) in comparison with flies maintained on standard diet. Exposure to high sucrose diet decreased body weight of Oregon (but not vermilion) imago. Attenuation of high sucrose diet-induced IR/T2D in vermilion flies might depend on deficiency of TRP - KYN pathway. Besides IR/T2D, HSD induces obesity in Drosophila. Future studies of HSD-induced obesity and IR/T2D in TDO deficient vermilion mutants of Drosophila might help to understand the mechanisms of high association between IR/T2D and obesity. Modulation of TRP - KYN metabolism might be utilized for prevention and treatment of IR/T2D.
Inflammation is elevated in obese pregnant women and is associated with adverse maternal and neonatal outcomes. Maternal lipid metabolism and its relationships with maternal inflammation, insulin resistance and neonatal metabolic health are poorly understood in obese pregnant women. 18 lean (age: 26.1 ± 5.0 years, pre-pregnancy BMI: 21.5 ± 1.9 kg/m2) and 16 obese (age: 25.0 ± 4.8 years, pre-pregnancy BMI: 36.3 ± 4.3 kg/m2) women participated in this case-control study during the third trimester of pregnancy. Maternal plasma markers of insulin resistance (HOMA-IR) and inflammation (C-reactive protein (CRP)) were measured at rest, and lipid concentration and kinetics (lipid oxidation rate and lipolysis) were measured at rest, during a 30-minute bout of low-intensity (40% VO2peak) exercise, and during a recovery period. Umbilical cord blood was collected for measurement of neonatal plasma insulin sensitivity, inflammation, and lipid concentration. Neonatal body composition was measured via air displacement plethysmography. Pregnant obese women had higher plasma CRP (9.1 ± 4.0 mg/L versus 2.3 ± 1.8 mg/L, p<0.001) and higher HOMA-IR (3.8 ± 1.9 versus 2.3 ± 1.5, p=0.009) compared to pregnant lean women. Obese women had higher lipid oxidation rates during recovery from low-intensity exercise (0.13 ± 0.03 g/min versus 0.11 ±0.04 g/min, p=0.02) that was associated with higher maternal CRP (r=0.55, p=0.001). Maternal CRP was positively associated with maternal HOMA-IR (r=0.40, p<0.02) and systolic blood pressure (r=0.40, p<0.02). Maternal lipid metabolism-associated inflammation may contribute to insulin resistance and higher blood pressure in obese women during pregnancy.