Vanita R. Aroda

Long-term safety, tolerability, and weight loss associated with metformin in the diabetes prevention program outcomes study

OBJECTIVE Metformin produced weight loss and delayed or prevented diabetes in the Diabetes Prevention Program (DPP). We examined its long-term safety and tolerability along with weight loss, and change in waist circumference during the DPP and its long-term follow-up. RESEARCH DESIGN AND METHODS The randomized double-blind clinical trial of metformin or placebo followed by a 7–8-year open-label extension and analysis of adverse events, tolerability, and the effect of adherence on change in weight and waist circumference. RESULTS No significant safety issues were identified. Gastrointestinal symptoms were more common in metformin than placebo participants and declined over time. During the DPP, average hemoglobin and hematocrit levels were slightly lower in the metformin group than in the placebo group. Decreases in hemoglobin and hematocrit in the metformin group occurred during the first year following randomization, with no further changes observed over time. During the DPP, metformin participants had reduced body weight and waist circumference compared with placebo (weight by 2.06 ± 5.65% vs. 0.02 ± 5.52%, P < 0.001, and waist circumference by 2.13 ± 7.06 cm vs. 0.79 ± 6.54 cm, P < 0.001 in metformin vs. placebo, respectively). The magnitude of weight loss during the 2-year double-blind period was directly related to adherence (P < 0.001). Throughout the unblinded follow-up, weight loss remained significantly greater in the metformin group than in the placebo group (2.0 vs. 0.2%, P < 0.001), and this was related to the degree of continuing metformin adherence (P < 0.001). CONCLUSIONS Metformin used for diabetes prevention is safe and well tolerated. Weight loss is related to adherence to metformin and is durable for at least 10 years of treatment.

The Effect of Lifestyle Intervention and Metformin on Preventing or Delaying Diabetes Among Women With and Without Gestational Diabetes: The Diabetes Prevention Program Outcomes Study 10-Year Follow-Up

CONTEXT Gestational diabetes (GDM) confers a high risk of type 2 diabetes. In the Diabetes Prevention Program (DPP), intensive lifestyle (ILS) and metformin prevented or delayed diabetes in women with a history of GDM. OBJECTIVE The objective of the study was to evaluate the impact of ILS and metformin intervention over 10 years in women with and without a history of GDM in the DPP/Diabetes Prevention Program Outcomes Study. DESIGN This was a randomized controlled clinical trial with an observational follow-up. SETTING The study was conducted at 27 clinical centers. PARTICIPANTS Three hundred fifty women with a history of GDM and 1416 women with previous live births but no history of GDM participated in the study. The participants had an elevated body mass index and fasting glucose and impaired glucose tolerance at study entry. INTERVENTIONS Interventions included placebo, ILS, or metformin. OUTCOMES MEASURE Outcomes measure was diabetes mellitus. RESULTS Over 10 years, women with a history of GDM assigned to placebo had a 48% higher risk of developing diabetes compared with women without a history of GDM. In women with a history of GDM, ILS and metformin reduced progression to diabetes compared with placebo by 35% and 40%, respectively. Among women without a history of GDM, ILS reduced the progression to diabetes by 30%, and metformin did not reduce the progression to diabetes. CONCLUSIONS Women with a history of GDM are at an increased risk of developing diabetes. In women with a history of GDM in the DPP/Diabetes Prevention Program Outcomes Study, both lifestyle and metformin were highly effective in reducing progression to diabetes during a 10-year follow-up period. Among women without a history of GDM, lifestyle but not metformin reduced progression to diabetes.

Polycystic ovary syndrome is associated with tissue-specific differences in insulin resistance.

OBJECTIVE The potential differential contributions of skeletal muscle and adipose tissue to whole body insulin resistance were evaluated in subjects with polycystic ovary syndrome (PCOS). RESEARCH DESIGN AND METHODS Forty-two PCOS subjects and 15 body mass index-matched control subjects were studied. Insulin action was evaluated by the hyperinsulinemic/euglycemic clamp procedure. Isolated adipocytes and cultured muscle cells were analyzed for glucose transport activity; adipocytes, muscle tissue, and myotubes were analyzed for the expression and phosphorylation of insulin-signaling proteins. RESULTS Fifty-seven per cent of the PCOS subjects had impaired glucose tolerance and the lowest rate of maximal insulin-stimulated whole body glucose disposal compared to controls (P < 0.01). PCOS subjects with normal glucose tolerance had intermediate reduction in glucose disposal rate (P < 0.05 vs. both control and impaired glucose tolerance subjects). However, rates of maximal insulin-stimulated glucose transport (insulin responsiveness) into isolated adipocytes were comparable between all three groups, whereas PCOS subjects displayed impaired insulin sensitivity. In contrast, myotubes from PCOS subjects displayed reduced insulin responsiveness for glucose uptake and normal sensitivity. There were no differences between groups in the expression of glucose transporter 4 or insulin-signaling proteins or maximal insulin stimulation of phosphorylation of Akt in skeletal muscle, myotubes, or adipocytes. CONCLUSIONS Individuals with PCOS display impaired insulin responsiveness in skeletal muscle and myotubes, whereas isolated adipocytes display impaired insulin sensitivity but normal responsiveness. Skeletal muscle and adipose tissue contribute differently to insulin resistance in PCOS. Insulin resistance in PCOS cannot be accounted for by differences in the expression of selected signaling molecules or maximal phosphorylation of Akt.

The safety and tolerability of GLP‐1 receptor agonists in the treatment of type 2 diabetes: a review

Although several classes of pharmacotherapy are available for type 2 diabetes, glycaemic control is often hampered by medication‐related adverse effects and contraindications such as renal impairment. Glucagon‐like peptide‐1 (GLP‐1) receptor agonists provide a new pharmacotherapeutic option based on the multiple glucose‐lowering effects of the human hormone GLP‐1. This mechanism of action not only provides therapeutic efficacy but also suggests that GLP‐1 receptor agonists have distinct safety and tolerability concerns compared with other diabetes therapies. Stimulation of pancreatic insulin secretion by GLP‐1 receptor agonists is glucose dependent, conferring a lesser risk of hypoglycaemia than that seen with sulfonylureas. Individual GLP‐1 receptor agonists differ in their metabolism and excretion profiles, affecting the choice of agent for patients with renal impairment. As with other protein‐based therapies, GLP‐1 receptor agonists may induce the formation of antibodies that may attenuate therapeutic efficacy and affect safety. Conclusions on cardiovascular safety must await outcomes studies, but at present no signal of harm has been reported, and preclinical data and effects on risk markers suggest a potential for benefit. Current data on thyroid medullary cancer in humans and pancreatic malignancy in rodents do not suggest that there is any reason to restrict the clinical use of GLP‐1 analogues in most people with diabetes. It is currently difficult to ascertain the possible contributory role of GLP‐1 receptor agonists in increasing the risk of pancreatitis, and vigilance for signs and symptoms is prudent. Primary tolerability issues include transient gastrointestinal symptoms, common with GLP‐1 receptor agonists, which can be reduced through dose titration. Copyright

Approach to the Patient with Prediabetes

Prediabetes consists of impaired fasting glucose and/or impaired glucose tolerance and is a significant risk factor for the development of type 2 diabetes, microvascular, and macrovascular disease. The values used to define prediabetes are arbitrary, because prediabetes represents an intermediary category along the continuum from normal glucose levels and tolerance to overt hyperglycemia. The progression from prediabetes to type 2 diabetes occurs over many years, strong evidence to support intervention to delay the progression from prediabetes to diabetes. Large, randomized prospective studies with lifestyle intervention and/or various modes of pharmacotherapy have demonstrated successful delay of diabetes. Several issues in the management of prediabetes remain controversial, such as the role of pharmacotherapy and when to escalate treatment. This article will review some of the issues surrounding the identification and treatment of prediabetes, with an interpretation of the available data to help guide management.

Efficacy and Safety of LixiLan, a Titratable Fixed-Ratio Combination of Insulin Glargine Plus Lixisenatide in Type 2 Diabetes Inadequately Controlled on Basal Insulin and Metformin: The LixiLan-L Randomized Trial

OBJECTIVE This study was conducted to demonstrate the efficacy and safety of LixiLan (iGlarLixi), a novel, titratable, fixed-ratio combination of insulin glargine (iGlar) (100 units) and lixisenatide, compared with iGlar in patients with type 2 diabetes inadequately controlled on basal insulin with or without up to two oral glucose-lowering agents. RESEARCH DESIGN AND METHODS After a 6-week run-in when iGlar was introduced and/or further titrated, and oral antidiabetic drugs other than metformin were stopped, 736 basal insulin-treated patients (mean diabetes duration 12 years, BMI 31 kg/m2) were randomized 1:1 to open-label, once-daily iGlarLixi or iGlar, both titrated to fasting plasma glucose <100 mg/dL (<5.6 mmol/L) up to a maximum dose of 60 units/day. The primary outcome was change in HbA1c levels at 30 weeks. RESULTS HbA1c decreased from 8.5% (69 mmol/mol) to 8.1% (65 mmol/mol) during the run-in period. After randomization, iGlarLixi showed greater reductions in HbA1c from baseline compared with iGlar (–1.1% vs. –0.6%, P < 0.0001), reaching a mean final HbA1c of 6.9% (52 mmol/mol) compared with 7.5% (58 mmol/mol) for iGlar. HbA1c <7.0% (53 mmol/mol) was achieved in 55% of iGlarLixi patients compared with 30% on iGlar. Mean body weight decreased by 0.7 kg with iGlarLixi and increased by 0.7 kg with iGlar (1.4 kg difference, P < 0.0001). Documented symptomatic hypoglycemia (≤70 mg/dL) was comparable between groups. Mild gastrointestinal adverse effects were very low but more frequent with iGlarLixi. CONCLUSIONS Compared with iGlar, a substantially higher proportion of iGlarLixi-treated patients achieved glycemic targets with a beneficial effect on body weight, no additional risk of hypoglycemia, and low levels of gastrointestinal adverse effects in inadequately controlled, basal insulin-treated, long-standing type 2 diabetes.

Scientific Statement: Socioecological Determinants of Prediabetes and Type 2 Diabetes

In this article, we examine the socioecological determinants—the biological, geographic, and built environment factors—that influence risk for prediabetes and type 2 diabetes. A socioecological perspective looks beyond the individual to evaluate a multitude of influences, from the surrounding home, work, school, and community environments to social determinants and the influence of public policy on individual behavior (1). Figure 1, adapted from the Institute of Medicine socioecological model of childhood obesity, provides a good framework for understanding potential socioecological determinants of risk for type 2 diabetes. Figure 1 Levels and sectors of influence on obesity and diabetes risk (progress in preventing childhood obesity) (© 2007 the National Academies Press). SES, socioeconomic status. In November 2012, the American Diabetes Association Prevention Committee convened a writing group to review the evidence on socioecological factors contributing to recent increases in prediabetes and type 2 diabetes. Drawing from the work of the committee, in this article we review the overarching evidence-based contributions of socioecological factors to risk for type 2 diabetes. Rather than incorporate the entire universe of relational observations, this scientific statement is intended to evaluate the extent to which data indicate a contributing role of social and environmental factors to the current epidemic of type 2 diabetes. The world is in the midst of parallel and rapidly advancing epidemics—obesity and type 2 diabetes—that began in the latter half of the 20th century and continue to grow, unchecked. Current prevalence rates are staggering and are expected to continue to climb over the ensuing decades. In the U.S., one-third of adults and 16–18% of youth are obese (2), up from 5 to 6% three decades ago (Fig. 2). Increases in rates of type 2 diabetes have closely followed the increases in obesity. In the U.S., diabetes affects 8.3% of the population, including 18.8 million with diagnosed …

Metabolic and Hormonal Changes Induced by Pioglitazone in Polycystic Ovary Syndrome: A Randomized, Placebo-Controlled Clinical Trial

CONTEXT Polycystic ovary syndrome (PCOS) is characterized by insulin resistance, compensatory hyperinsulinemia, increased prevalence of impaired glucose tolerance, and increased ovarian androgen biosynthesis. OBJECTIVE The aim of the study was to evaluate effects of pioglitazone on whole body insulin action and ovarian androgen biosynthesis in PCOS. DESIGN We performed a randomized placebo-controlled trial. SETTING The study was conducted at the Special Diagnostic and Treatment Unit of the Veterans Affairs Medical Center, San Diego, and the University of California, San Diego, General Clinical Research Center. PATIENTS OR OTHER PARTICIPANTS A total of 23 subjects with PCOS were evaluated at baseline and end of treatment. Six age- and body mass index-matched women without PCOS were normal controls for baseline evaluation. INTERVENTION Subjects with PCOS were randomized to oral placebo or pioglitazone 45 mg daily for 6 months. MAIN OUTCOME MEASURE(S) The primary outcome measures were whole body insulin action as measured by hyperinsulinemic euglycemic clamp and ovarian androgen biosynthesis as measured by leuprolide-stimulated production of 17-hydroxyprogesterone (17-OHP). RESULTS Compared with placebo, pioglitazone treatment significantly improved multiple measures of insulin action, including glucose disposal rate (P < 0.01), 2-h glucose during 75-g oral glucose tolerance test (P < 0.01), area under the curve glucose during oral glucose tolerance test (P < 0.01), serum adiponectin (P < 0.01), and fasting hyperinsulinemia (P < 0.01). Compared to placebo, pioglitazone treatment reduced the increment of leuprolide-stimulated 17-OHP (P < 0.02). Improvements in glucose disposal rate correlated with reductions in 17-OHP stimulation (P < 0.02). CONCLUSIONS Compared to placebo, pioglitazone treatment in PCOS was associated with improvements in insulin action and glucose homeostasis and ameliorated the hyperandrogenic ovarian response.

Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study.

CONTEXT Vitamin B12 deficiency may occur with metformin treatment, but few studies have assessed risk with long-term use. OBJECTIVE To assess the risk of B12 deficiency with metformin use in the Diabetes Prevention Program (DPP)/DPP Outcomes Study (DPPOS). DESIGN Secondary analysis from the DPP/DPPOS. Participants were assigned to the placebo group (PLA) (n = 1082) or the metformin group (MET) (n = 1073) for 3.2 years; subjects in the metformin group received open-label metformin for an additional 9 years. SETTING Twenty-seven study centers in the United States. PATIENTS DPP eligibility criteria were: elevated fasting glucose, impaired glucose tolerance, and overweight/obesity. The analytic population comprised participants with available stored samples. B12 levels were assessed at 5 years (n = 857, n = 858) and 13 years (n = 756, n = 764) in PLA and MET, respectively. INTERVENTION Metformin 850 mg twice daily vs placebo (DPP), and open-label metformin in the metformin group (DPPOS). MAIN OUTCOME MEASURES B12 deficiency, anemia, and peripheral neuropathy. RESULTS Low B12 (≤ 203 pg/mL) occurred more often in MET than PLA at 5 years (4.3 vs 2.3%; P = .02) but not at 13 years (7.4 vs 5.4%; P = .12). Combined low and borderline-low B12 (≤ 298 pg/mL) was more common in MET at 5 years (19.1 vs 9.5%; P < .01) and 13 years (20.3 vs 15.6%; P = .02). Years of metformin use were associated with increased risk of B12 deficiency (odds ratio, B12 deficiency/year metformin use, 1.13; 95% confidence interval, 1.06–1.20). Anemia prevalence was higher in MET, but did not differ by B12 status. Neuropathy prevalence was higher in MET with low B12 levels. CONCLUSIONS Long-term use of metformin in DPPOS was associated with biochemical B12 deficiency and anemia. Routine testing of vitamin B12 levels in metformin-treated patients should be considered.

Efficacy and safety of once-weekly semaglutide versus once-daily insulin glargine as add-on to metformin (with or without sulfonylureas) in insulin-naive patients with type 2 diabetes (SUSTAIN 4): a randomised, open-label, parallel-group, multicentre, multinational, phase 3a trial

BACKGROUND Several pharmacological treatment options are available for type 2 diabetes; however, many patients do not achieve optimum glycaemic control and therefore new therapies are necessary. We assessed the efficacy and safety of semaglutide, a glucagon-like peptide-1 (GLP-1) analogue in clinical development, compared with insulin glargine in patients with type 2 diabetes who were inadequately controlled with metformin (with or without sulfonylureas). METHODS We did a randomised, open-label, non-inferiority, parallel-group, multicentre, multinational, phase 3a trial (SUSTAIN 4) at 196 sites in 14 countries. Eligible participants were insulin-naive patients with type 2 diabetes, aged 18 years and older, who had insufficient glycaemic control with metformin either alone or in combination with a sulfonylurea. We randomly assigned participants (1:1:1) to either subcutaneous once-weekly 0·5 mg or 1·0 mg semaglutide (doses reached after following a fixed dose-escalation regimen) or once-daily insulin glargine (starting dose 10 IU per day, then titrated weekly to a pre-breakfast self-measured plasma glucose target of 4·0-5·5 mmol/L [72-99 mg/dL]) for 30 weeks. In all treatment groups, previous background metformin and sulfonylurea treatment was continued throughout the trial. We did the randomisation using an interactive voice or web response system. The primary endpoint was change in mean HbA1c from baseline to week 30 and the confirmatory secondary endpoint was the change in mean bodyweight from baseline to week 30. We assessed efficacy and safety in the modified intention-to-treat population (mITT; all randomly assigned participants who were exposed to at least one dose of study drug) and used a margin of 0·3% to establish non-inferiority in HbA1c reduction. This trial is registered with ClinicalTrials.gov, number NCT02128932. FINDINGS Between Aug 4, 2014, and Sept 3, 2015, we randomly assigned 1089 participants to treatment; the mITT population consisted of 362 participants assigned to 0·5 mg semaglutide, 360 to 1·0 mg semaglutide, and 360 to insulin glargine. 49 (14%) participants assigned to 0·5 mg semaglutide discontinued treatment prematurely, compared with 55 (15%) assigned to 1·0 mg semaglutide, and 26 (7%) assigned to insulin glargine. Most discontinuations were due to adverse events-mostly gastrointestinal with semaglutide, and others such as skin and subcutaneous tissue disorders (eg, rash, pruritus, and urticaria) with insulin glargine. From a mean baseline HbA1c of 8·17% (SD 0·89), at week 30, 0·5 and 1·0 mg semaglutide achieved reductions of 1·21% (95% CI 1·10-1·31) and 1·64% (1·54-1·74), respectively, versus 0·83% (0·73-0·93) with insulin glargine; estimated treatment difference versus insulin glargine -0·38% (95% CI -0·52 to -0·24) with 0·5 mg semaglutide and -0·81% (-0·96 to -0·67) with 1·0 mg semaglutide (both p<0·0001). Mean bodyweight at baseline was 93·45 kg (SD 21·79); at week 30, 0·5 and 1·0 mg semaglutide achieved weight losses of 3·47 kg (95% CI 3·00-3·93) and 5·17 kg (4·71-5·66), respectively, versus a weight gain of 1·15 kg (0·70-1·61) with insulin glargine; estimated treatment difference versus insulin glargine -4·62 kg (95% CI -5·27 to -3·96) with 0·5 mg semaglutide and -6·33 kg (-6·99 to -5·67) with 1·0 mg semaglutide (both p<0·0001). Severe or blood glucose-confirmed hypoglycaemia was reported by 16 (4%) participants with 0·5 mg semaglutide and 20 (6%) with 1·0 mg semaglutide versus 38 (11%) with insulin glargine (p=0·0021 and p=0·0202 for 0·5 mg and 1·0 mg semaglutide vs insulin glargine, respectively). Severe hypoglycaemia was reported by two (<1%) participants with 0·5 mg semaglutide, five (1%) with 1·0 mg semaglutide, and five (1%) with insulin glargine. Six deaths were reported: four (1%) in the 0·5 mg semaglutide group (three cardiovascular deaths, one pancreatic carcinoma, which was assessed as being possibly related to study medication) and two (<1%) in the insulin glargine group (both cardiovascular death). The most frequently reported adverse events were nausea with semaglutide, reported in 77 (21%) patients with 0·5 mg and in 80 (22%) with 1·0 mg, and nasopharyngitis reported in 44 (12%) patients with insulin glargine. INTERPRETATION Compared with insulin glargine, semaglutide resulted in greater reductions in HbA1c and weight, with fewer hypoglycaemic episodes, and was well tolerated, with a safety profile similar to that of other GLP-1 receptor agonists. FUNDING Novo Nordisk A/S.