HARMONY 4: randomised clinical trial comparing once-weekly albiglutide and insulin glargine in patients with type 2 diabetes inadequately controlled with metformin with or without sulfonylurea

Aims/hypothesis

The aim of this study was to compare the efficacy and safety of once-weekly albiglutide with once-daily insulin glargine (A21Gly,B31Arg,B32Arg human insulin) in patients with type 2 diabetes inadequately controlled on metformin with or without sulfonylurea.

Methods

This was a randomised, open-label, multicentre (n?=?222), parallel-group, non-inferiority out-patient clinical trial, with 779 patients enrolled in the study. The study was conducted in 222 centres located in four countries. Patients aged ≥18 years with type 2 diabetes treated with metformin (±sulfonylurea) for at least 3 months with a baseline HbA_1c 7.0–10.0% (53.0–85.8 mmol/mol) were randomly assigned (2:1) via a computer-generated randomisation sequence with a voice response system to receive albiglutide (30 mg once a week, n?=?504) or insulin glargine (10 U once a day, n?=?241) added to current therapy. Participants and investigators were not masked to treatment assignment. Doses of each medication were adjusted on the basis of the glycaemic response. The primary endpoint was change from baseline in HbA_1c at week 52.

Results

In the albiglutide group, HbA_1c declined from 8.28?±?0.90% (67.0?±?9.8 mmol/mol) (mean?±?SD) at baseline to 7.62?±?1.12% (59.8?±?12.2 mmol/mol) at week 52. A similar reduction occurred in the insulin glargine group (8.36?±?0.95% to 7.55?±?1.04% [67.9?±?10.4 to 59.0?±?11.4 mmol/mol]). The model-adjusted treatment difference of 0.11% (95% CI ?0.04%, 0.27%) (1.2 mmol/mol [95% CI ?0.4, 3.0 mmol/mol]) indicated non-inferiority of albiglutide to insulin glargine based on the pre-specified non-inferiority margin of 0.3% (3.3 mmol/mol, p?=?0.0086). Body weight increased in the insulin glargine group and decreased in the albiglutide group, with a mean treatment difference of ?2.61 kg (95% CI ?3.20, ?2.02; p?p?=?0.0377).

Conclusions/interpretation

Albiglutide was non-inferior to insulin glargine at reducing HbA_1c at week 52, with modest weight loss and less hypoglycaemia. Both drugs were well tolerated. Albiglutide may be considered an alternative to insulin glargine in this patient population. Trial registration: ClinicalTrials.gov NCT00838916 (completed) Funding: This study was planned and conducted by GlaxoSmithKline.     

Reductions in arterial stiffness with weight loss in overweight and obese young adults: Potential mechanisms

ObjectiveArterial stiffness decreases with weight loss in overweight/obese young adults. We aimed to determine the mechanisms by which this occurs.MethodsWe evaluated carotid-femoral pulse wave velocity (cfPWV) and brachial-ankle pulse wave velocity (baPWV) in 344 young adults (23% male, BMI 25–40 kg/m²) at baseline, 6, and 12 months in a behavioral weight loss intervention. Linear mixed models were used to evaluate associations between weight loss and arterial stiffness and to examine whether improvements in obesity-related factors explained these associations.ResultsAt 6 months (7% mean weight loss), there was a significant median decrease of 47.5 cm/s in cfPWV (p < 0.0001) and a mean decrease of 11.7 cm/s in baPWV (p = 0.049). At 12 months (6% mean weight loss), only cfPWV remained reduced. In models adjusting for changes in mean arterial pressure and obesity-related factors, changes in BMI (p = 0.01) and common carotid artery diameter (p = 0.003) were positively associated with change in cfPWV. Reductions in heart rate (p < 0.0001) and C-reactive protein (p = 0.02) were associated with reduced baPWV and accounted for the association between weight loss and reduced baPWV.ConclusionsWeight loss is associated with reduced cfPWV independently of changes in established hemodynamic and cardiometabolic risk factors, but its association with reduced baPWV is explained by concurrent reductions in heart rate and inflammation.     

The role of intracellular calcium phosphate in osteoblast-mediated bone apatite formation

Mineralization is a ubiquitous process in the animal kingdom and is fundamental to human development and health. Dysfunctional or aberrant mineralization leads to a variety of medical problems, and so an understanding of these processes is essential to their mitigation. Osteoblasts create the nano-composite structure of bone by secreting a collagenous extracellular matrix (ECM) on which apatite crystals subsequently form. However, despite their requisite function in building bone and decades of observations describing intracellular calcium phosphate, the precise role osteoblasts play in mediating bone apatite formation remains largely unknown. To better understand the relationship between intracellular and extracellular mineralization, we combined a sample-preparation method that simultaneously preserved mineral, ions, and ECM with nano-analytical electron microscopy techniques to examine osteoblasts in an in vitro model of bone formation. We identified calcium phosphate both within osteoblast mitochondrial granules and intracellular vesicles that transported material to the ECM. Moreover, we observed calcium-containing vesicles conjoining mitochondria, which also contained calcium, suggesting a storage and transport mechanism. Our observations further highlight the important relationship between intracellular calcium phosphate in osteoblasts and their role in mineralizing the ECM. These observations may have important implications in deciphering both how normal bone forms and in understanding pathological mineralization.     

Tumor suppression by cell competition through regulation of the Hippo pathway

Homeostatic mechanisms can eliminate abnormal cells to prevent diseases such as cancer. However, the underlying mechanisms of this surveillance are poorly understood. Here we investigated how clones of cells mutant for the neoplastic tumor suppressor gene scribble (scrib) are eliminated from Drosophila imaginal discs. When all cells in imaginal discs are mutant for scrib, they hyperactivate the Hippo pathway effector Yorkie (Yki), which drives growth of the discs into large neoplastic masses. Strikingly, when discs also contain normal cells, the scrib(-) cells do not overproliferate and eventually undergo apoptosis through JNK-dependent mechanisms. However, induction of apoptosis does not explain how scrib(-) cells are prevented from overproliferating. We report that cell competition between scrib(-) and wild-type cells prevents hyperproliferation by suppressing Yki activity in scrib(-) cells. Suppressing Yki activation is critical for scrib(-) clone elimination by cell competition, and experimental elevation of Yki activity in scrib(-) cells is sufficient to fuel their neoplastic growth. Thus, cell competition acts as a tumor-suppressing mechanism by regulating the Hippo pathway in scrib(-) cells.     

The ABO blood group is a trans-species polymorphism in primates

The ABO histo-blood group, the critical determinant of transfusion incompatibility, was the first genetic polymorphism discovered in humans. Remarkably, ABO antigens are also polymorphic in many other primates, with the same two amino acid changes responsible for A and B specificity in all species sequenced to date. Whether this recurrence of A and B antigens is the result of an ancient polymorphism maintained across species or due to numerous, more recent instances of convergent evolution has been debated for decades, with a current consensus in support of convergent evolution. We show instead that genetic variation data in humans and gibbons as well as in Old World monkeys are inconsistent with a model of convergent evolution and support the hypothesis of an ancient, multiallelic polymorphism of which some alleles are shared by descent among species. These results demonstrate that the A and B blood groups result from a trans-species polymorphism among distantly related species and has remained under balancing selection for tens of millions of years—to date, the only such example in hominoids and Old World monkeys outside of the major histocompatibility complex.     

Lead poisoning and the deceptive recovery of the critically endangered California condor

Endangered species recovery programs seek to restore populations to self-sustaining levels. Nonetheless, many recovering species require continuing management to compensate for persistent threats in their environment. Judging true recovery in the face of this management is often difficult, impeding thorough analysis of the success of conservation programs. We illustrate these challenges with a multidisciplinary study of one of the world's rarest birds-the California condor (Gymnogyps californianus). California condors were brought to the brink of extinction, in part, because of lead poisoning, and lead poisoning remains a significant threat today. We evaluated individual lead-related health effects, the efficacy of current efforts to prevent lead-caused deaths, and the consequences of any reduction in currently intensive management actions. Our results show that condors in California remain chronically exposed to harmful levels of lead; 30% of the annual blood samples collected from condors indicate lead exposure (blood lead ≥ 200 ng/mL) that causes significant subclinical health effects, measured as >60% inhibition of the heme biosynthetic enzyme δ-aminolevulinic acid dehydratase. Furthermore, each year, ～20% of free-flying birds have blood lead levels (≥450 ng/mL) that indicate the need for clinical intervention to avert morbidity and mortality. Lead isotopic analysis shows that lead-based ammunition is the principle source of lead poisoning in condors. Finally, population models based on condor demographic data show that the condor's apparent recovery is solely because of intensive ongoing management, with the only hope of achieving true recovery dependent on the elimination or substantial reduction of lead poisoning rates.