Risk factors for spontaneously self-reported postprandial hypoglycemia after bariatric surgery
Monica Nannipieri et al. Journal of Clinical Endocrinology & Metabolism. Doi: http://dx.doi.org/10.1210/jc.2016-1143
Bariatric surgery is often seen as a quick and easy solution for obesity, especially as surgical techniques have developed with techniques varying from causing malabsorption (such as Roux-en-Y bypass – RYGB) to those reducing stomach size (gastric band and laparoscopic sleeve gastrectomy – LSG). However, many of these techniques result in significant post-operative symptoms including post prandial hypoglycaemia (PPHG) which can be disabling. As a result, patient selection for bariatric surgery is important in order to achieve the best outcomes as is post-operative follow up. This study examined some of the predictive indicators for PPHG in self-reporting groups of patients following both procedures using glucose tolerance tests in an attempt to reproduce it. In patients self-reporting PPHG following both procedures, lower pre-surgery fasting and post prandial glucose levels, higher insulin sensitivity and better β cell function were found to be significant predictors of PPHG or, put another way, the more insulin resistant the patient is pre-operatively, the less likely they are to suffer PPHG.
Distinct clinical characteristics and therapeutic modalities for diabetic ketoacidosis in type 1 and type 2 diabetes mellitus
Yuji Kamata et al. Journal of Diabetes and Its Complications. Doi: http://dx.doi.org/10.1016/j.jdiacomp.2016.06.023
Diabetic ketoacidosis (DKA) is a relatively common complication of Type 1 diabetes (T1DM). However, a combination of increasing insulin deficiency and insulin resistance can result in DKA in patients with T2DM often in older, non-white patients sometimes presenting with diabetes for the first time and as a result, can have a higher mortality than in T1DM. Although the basic treatment is the same whatever the underlying cause (fluids, potassium and insulin), the exact clinical characteristics of the patients and intensity of treatment is unclear and was therefore examined in this retrospective study which compared the clinical features and treatment of 127 T1 and 74 T2 patients who presented between 2001 and 2014. Whilst infections were the main trigger for DKA in T1DM, sugary drink consumption was the main precipitating cause in T2DM. The latter tended to have higher glucose levels on presentation with more serious renal dysfunction. T2 patients also required a higher insulin dose, larger fluid replacement volumes and greater potassium supplementation. Given this, perhaps specific guidelines should be developed for them. Although these patients tender to be sicker, the majority recover but specialist input is important when decisions about long term treatment are made as not all these patients will require insulin.
Gastric bypass reduces symptoms and hormonal responses in hypoglycemia
Niclas Abrahamsson et al. Diabetes. Doi: http://dx.doi.org/10.2337/db16-0341
As well as causing weight loss by mechanical effects, gastric bypass surgery also has an impact on metabolic parameters, specifically its impact on gut and counter regulatory hormones. Commonly these patients also have lower glucose levels and frequent asymptomatic episodes of hypoglycaemia. Using a hyperinsulinaemic, hypoglycaemic clamp this study subjected patients to hypoglycaemia (2.7mmol/l) pre and post procedure and examined symptoms, hormonal and autonomic nerve responses in 12 obese non diabetic patients. Post surgery, symptoms were attenuated and there were also marked reductions in glucagon, cortisol, catecholamines and sympathetic nervous response. The rise in GLP-1 was also reduced post surgery. In summary, the study showed that gastric bypass surgery caused a reset in glucose homeostasis which reduces the body’s response to hypoglycaemia both metabolically and symptomatically. Given the potential for significant post operatives problems caused by hypoglycaemia, this study reinforces the need to select patients for bariatric surgery as well as arranging their long term follow up.
Long-term cognitive implications of intrauterine hyperglycemia in adolescent offspring of women with T1D (the EPICOM study)
Birgitte Bytoft et al. Diabetes Care. Doi: http://dx.doi.org/10.2337/dc16-0168
Pregnancy and diabetes are not good bed-fellows. Chose any unwanted outcome, both maternal and foetal, and its likelihood is increased by the presence of maternal hyperglycaemia. This study adds another downside to the extensive list. The EPICOM study is a prospectively followed cohort of women with type 1 diabetes (T1DM). In this study, the offspring of 277 participants had evaluation of cognitive function aged 13-19 years. Comparisons were made with a controls (N=301) taken from the background population. Study offspring scored lower in all intelligence indices: composite intelligence (95.7 vs. 100, P = 0.001), verbal intelligence (96.2 vs. 100, P = 0.004), nonverbal intelligence (96.4 vs. 100, P = 0.008), and composite memory (95.7 vs. 100, P = 0.001). A higher frequency also had parent-reported learning difficulties in primary school, implying that these differences can be clinically relevant. Perhaps the only positive outcome of the study was that there was no correlation between offspring cognitive function and maternal HbA1c so these data should not promote further reductions in HbA1c targets for T1DM patients contemplating pregnancy – the current levels are impossible for many women…
Dipeptidyl peptidase-4 inhibitors and bone metabolism: is vitamin D the link?
Barchetta et al. Acta Diabetologica. Doi: 10.1007/s00592-016-0882-9
The interaction between type 2 diabetes (T2DM) and bone metabolism was first highlighted by reports of increased risk of fracture in women taking the thiazolidinedione (TZD) rosiglitazone in the ADOPT study. This was a completely unexpected finding, which was subsequently found to be a class effect of the TZDs and is seen in both sexes. The reason for this side-effect remains unknown but it has led to new therapy classes for T2DM to be scrutinised for adverse events relating to bone and for investigation of their impact on bone metabolism. This publication examines serum 25(OH) vitamin D in 295 T2DM patients, 53% of whom were taking a DPP4-inhibitor. It reports significantly higher levels compared with patients taking other antidiabetic therapies (18.4 ± 10.7 vs. 14.9 ± 8.6 ng/ml, p = 0.004), an association which persisted after adjusting for major confounders. The authors suggest that this might explain ‘the positive effect of DPP-4 inhibitors on bone metabolism’; whether this equates to clinical benefit remains to be seen.