Diabetes surpasses obesity as a risk factor for low serum testosterone level

BACKGROUND

Male obesity is one of the most associated factors with substandard testosterone levels. However, there is growing evidence linking low testosterone levels to insulin resistance and diabetic complications. We aimed to study the impact of diabetes mellitus on testosterone levels and to assess the correlation of various clinical and biochemical factors with hypogonadism.

SUBJECTS AND METHODS

This case-control study was conducted on 160 adult males categorized into four equal groups (40 each); Group A: lean men with T2DM, Group B: obese with T2DM, Group C: lean with normal glycemic profile, Group D: obese with normal glycemic profile. Serum total testosterone (TT), SHBG and HbA1c have been measured. Free testosterone (cFT) and HOMA-IR were calculated.

RESULTS

A significant negative correlation of serum TT and cFTwith BMI (r -0.16, p 0.04/ r -0.26, p < 0.001, respectively) and with waist circumference (WC) (r -0.23, p 0.003 and r -0.3, p < 0.001, respectively). A significant decrease in TT and cFT in the diabetes group versus the non-diabetes one (p < 0.001 for both). TT level was significantly lower in the diabetic lean group than in the non-diabetic lean (p < 0.001), and even significantly lower than in the non-diabetic obese (p < 0.001). TT level in the diabetic obese group was lower than in the non-diabetic obese (p < 0.001). The same for cFT level, lower in the diabetic lean group than in non-diabetic lean (p < 0.001) and lower in the diabetic obese than in the non-diabetic obese (p < 0.001). Concomitant significant reduction in SHBG in the diabetes group (p < 0.001). Linear regression analysis revealed that TT significantly correlated with HOMA-IR. HOMA-IR with WC, age and the duration of diabetes correlated significantly with cFT. In our model, HOMA-IR and HbA1c accounted for approximately 51.3% of TT variability (adjusted R-squared 0.513).

CONCLUSIONS

The impact of T2DM on serum testosterone levels was more significant than that of obesity. Our study showed a decrease in SHBG together with cFT among the diabetes group. Hypogonadism is significantly correlated to insulin resistance and poor glycemic control, which implies another perspective on the impact of suboptimal glycemic control on the development of hypogonadism.

Glucose ingestion does not lower testosterone concentrations in men on testosterone therapy

Oral calorie intake causes an acute and transient decline in serum testosterone concentrations. It is not known whether this decline occurs in men on testosterone therapy. In this study, we evaluated the change in testosterone concentrations following oral glucose ingestion in hypogonadal men before and after treatment with testosterone therapy. This is a secondary analysis of samples previously collected from a study of hypogonadal men with type 2 diabetes who received testosterone therapy. Study participants (n = 14) ingested 75 grams of oral glucose, and blood samples were collected over 2 h. The test was repeated after 23 weeks of intramuscular testosterone therapy. The mean age and body mass index of study volunteers were 53 ± 8 years and 38 ± 7 kg/m2, respectively. Following glucose intake, testosterone concentrations fell significantly prior to testosterone therapy (week 0, p = 0.04). The nadir of testosterone concentration was at 1 h, followed by recovery to baseline by 2 h. In contrast, there was no change in testosterone concentrations at week 23. The change in serum testosterone concentrations at 60 min was significantly more at week 0 than week 23 (-11 ± 10% vs 0 ± 16%, p = 0.05). We conclude that oral glucose intake has no impact on testosterone concentrations in men on testosterone therapy. Endocrinology societies should consider clarifying in their recommendations that fasting testosterone concentrations are required for the diagnosis of hypogonadism, but not for monitoring testosterone therapy.

Glucagon-like peptide-1 receptor agonists as a possible intervention to delay the onset of type 1 diabetes: A new horizon

Type 1 diabetes (T1D) is a chronic autoimmune condition that destroys insulin-producing beta cells in the pancreas, leading to insulin deficiency and hyper-glycemia. The management of T1D primarily focuses on exogenous insulin replacement to control blood glucose levels. However, this approach does not address the underlying autoimmune process or prevent the progressive loss of beta cells. Recent research has explored the potential of glucagon-like peptide-1 receptor agonists (GLP-1RAs) as a novel intervention to modify the disease course and delay the onset of T1D. GLP-1RAs are medications initially developed for treating type 2 diabetes. They exert their effects by enhancing glucose-dependent insulin secretion, suppressing glucagon secretion, and slowing gastric emptying. Emerging evidence suggests that GLP-1RAs may also benefit the treatment of newly diagnosed patients with T1D. This article aims to highlight the potential of GLP-1RAs as an intervention to delay the onset of T1D, possibly through their potential immunomodulatory and anti-inflammatory effects and preservation of beta-cells. This article aims to explore the potential of shifting the paradigm of T1D management from reactive insulin replacement to proactive disease modification, which should open new avenues for preventing and treating T1D, improving the quality of life and long-term outcomes for individuals at risk of T1D.

Vasoactive mediators of hypertension in obesity

Obesity is associated with hypertension. However, the mechanisms involved are not fully understood. Therefore, we investigated the relationship between obesity and vasoactive mediators. In this cross-sectional study, blood pressure (BP) and vasoactive mediators of hypertension are compared among 135 adults in the nonobese, obese, and morbidly obese body mass index (BMI) ranges (BMI ≤27, 30-40, and >40 kg/m2, respectively). Angiotensinogen, angiotensin II, renin, aldosterone, endothelin-1 (ET-1), neprilysin, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), cyclic guanosine monophosphate (cGMP), and cyclic adenosine monophosphate (cAMP) levels were measured and their relationship to BP, BMI, race, and gender were investigated. Systolic and diastolic BP (SBP and DSP) were significantly higher in subjects with obesity and morbid obesity compared with nonobese. Angiotensin II, ET-1, and neprilysin were significantly higher in subjects with morbid obesity while BNP was lower. Levels of angiotensinogen, renin, aldosterone, ANP, cGMP, and cAMP did not differ between the groups. BMI was positively related to SBP, DBP, angiotensin II, ET-1, and neprilysin, and inversely related to cGMP and BNP. Age, male gender, and African-American race were associated with higher SBP. SBP was positively related to angiotensin II and ET-1 and inversely related to aldosterone, renin, and cGMP. On multivariate analyses, age, BMI, gender, and race were the main determinants of SBP, and excluding these variables, angiotensin II, aldosterone, renin, and ET-1 accounted for 21.1% ability to predict SBP. Obesity, especially morbid obesity, is associated with higher BP, higher angiotensin II and ET-1 (vasoconstrictors), and lower levels BNP and cGMP (vasodilators). SBP variability can be partly explained by angiotensin II, aldosterone, renin, and ET-1.NEW & NOTEWORTHY Our data show that obesity, especially morbid obesity, is associated with higher blood pressure levels and increases angiotensin II and endotherlin-1 (ET-1) (vasoconstrictors) and lower levels BNP and cGMP (vasodilators) and that systolic blood pressure variability can be partly explained by levels of angiotensin II, aldosterone, renin, and ET-1. The effect of these mediators on blood pressure is in addition to the effects of other known factors related to age, male gender, and AA race.

Insulin Resistance and Glycated Hemoglobin in Obesity Are Associated With Preference for Sugar-Sweetened Yogurt: A Pilot Study

OBJECTIVE

Insulin resistance is associated with elevated activation of food reward, which should be associated with an increased reinforcing value of food. Research has also shown that sugar is a macronutrient strongly associated with reward and reinforcing value of food. This research is designed to assess whether insulin resistance is associated with a stronger preference for sugar-sweetened, thus elevating blood glucose responses in obese people with varying degrees of insulin resistance.

METHODS

Thirteen people with obesity (body mass index, 39.1 kg/m 2 ; range, 30.0-45.1 kg/m 2 ) with varying degrees of insulin resistance (Homeostatic Model Assessment of Insulin Resistance, 5.2; range, 0.7-11.6) consumed novel flavored-colored yogurts that were sweetened with either sugar or monkfruit daily for 6 days to assess whether when given the choice of sugar-sweetened versus monkfruit-sweetened yogurts to consume, participants preferred sugar-sweetened yogurts.

RESULTS

Participants consumed a greater amount ( p = .009) and percentage ( p = .04) of sugar-sweetened yogurt earned than monkfruit-sweetened yogurt. The percent of sugar-sweetened versus monkfruit-sweetened yogurt consumed in relationship to amount earned was related to insulin resistance ( r = 0.64, p = .019), glycated hemoglobin ( r = 0.61, p = .027), insulin ( r = 0.58, p = .007), and glucose ( r = 0.56, p = .048).

CONCLUSIONS

Insulin resistance is associated with preference for sugar-sweetened foods in participants with obesity, which may make it hard to make dietary changes. Research is needed to assess whether treatments that improve insulin resistance also change the preference for sugar-sweetened or high-glycemic-index foods.

Omega-3 Fatty Acids in Cardiovascular Disease and Diabetes: a Review of Recent Evidence

PURPOSE OF REVIEW

Omega-3 fatty acids (n-3 FA) lower triglycerides, have anti-inflammatory properties, and improve metabolism. Clinical evidence of cardiovascular benefit with omega-3 fatty acids is mixed. We discuss mechanisms providing biological plausibility of benefit of omega-3 fatty acids in cardiovascular risk reduction and review clinical trials investigating the benefits of prescription omega-3 fatty acids in dyslipidemia, atherosclerotic cardiovascular disease (ASCVD), and diabetes.

RECENT FINDINGS

Although early trials showed no benefit of omega-3 fatty acids in ASCVD, the REDUCE-IT trial noted significant risk reduction in ASCVD events with highly purified EPA (icosapent ethyl) use which has changed the landscape for currently available therapeutic options. However, other large trials like STRENGTH and VITAL, which used different formulations of prescription omega-3 fatty acids, did not note significant cardiovascular risk reduction. Thus the effectiveness of omega-3 fatty acids for cardiovascular disease prevention is an ongoing topic of debate. A relative paucity of studies examining benefits for glycemic outcomes in persons with diabetes exists; however, few studies have suggested lack of benefit to date. Significant residual cardiovascular risk exists for individuals with hypertriglyceridemia. Prescription omega-3 fatty acids are more commonly used for CV risk reduction in these patients. Clinical guideline statements now recommend icosapent ethyl use for selected individuals with hypertriglyceridemia to reduce cardiovascular events given recent evidence from the REDUCE-IT trial. Nonetheless, data from other large scale trials has been mixed, and future research is needed to better understand how different preparations of omega-3 may differ in their cardiovascular and metabolic effects, and the mechanisms for their benefit.

Recognizing the True Value of Testosterone Therapy in Health Care

There has been little recognition within the medical community of the health impact of testosterone (T) deficiency (TD), also known as hypogonadism, and the substantial benefits of testosterone therapy (TTh) on health and quality of life despite high-level clinical evidence. In a roundtable symposium, investigators summarized the contemporary evidence in several key clinical areas. TD negatively impacts human health and quality of life and is associated with increased mortality. Several studies have demonstrated that TTh in men with TD reduced all-cause and cardiovascular mortality. The longstanding belief that TTh is associated with increased prostate cancer (PCa) risk is contradicted by recent evidence, including multiple studies showing that TTh is associated with reduced PCa risk. Similarly, the weight of current evidence indicates the purported concern that TTh is associated with increased cardiovascular risk is incorrect. Normalization of physiological T reduces myocardial infarction, stroke, and deaths compared with men whose testosterone levels failed to normalize. In diabetic men TTh improves insulin resistance, and a large 2-year controlled study in men with abnormal glucose tolerance showed a substantially reduced rate of diabetes among men treated with TTh compared with untreated controls. Long-term TTh in diabetic men resulted in progressive improvements in obesity and insulin requirements, including a substantial number who experienced complete remission of diabetes. Finally, TTh has been shown to reduce severe outcomes with Covid-19 infection. These lines of evidence argue strongly for the need for greater awareness in the medical community of the impact of TD on health, and of the health benefits of TTh.

LBSUN213 An Investigation Into The Effects Of Dapagliflozin On Ketogenesis In Type 1 Diabetes

Background

Treatment with sodium-glucose transporter (SGLT)-2 inhibitors in patients with type 1 diabetes (T1DM) is associated with increased ketogenesis and diabetic ketoacidosis (DKA). The exact relationship between SGLT-2 inhibitors use in T1DM and ketogenesis is not fully understood.

Patients and Methods

In this single center, randomized, double blind and placebo-controlled trial 70 patients with established T1DM were randomized into placebo, dapagliflozin (SGLT-2 inhibitor) alone, exenatide/Bydureon (short and long-term acting GLP-1 RA, respectively) alone or with dapagliflozin and exenatide/Bydureon (triple therapy) groups in addition to routine insulin treatment (titrated in all groups to reduce risk of hypoglycemia). Patients were tested acutely (single dose before and after 12 weeks of treatment) under extended fasting and insulinopenic conditions (stress conditions) and under basal fasting conditions during 12 weeks treatment period.

Results

At end of 12 weeks treatment, glycemic indices improved significantly compared to baseline in the dapagliflozin and Bydureon alone groups and improved significantly compared to placebo in the triple therapy group (HbA1c: -0.9±0.1%, p&lt;0. 001). Weight loss was significant (p&lt;0. 001) in all active treatment groups. Ketones (beta-hydroxybutyrate, BHB) increased significantly in blood (0.21±0. 04 to 1.57±0.21 mM) and urine under acute stress conditions in control group at baseline and at 12 weeks visits. The magnitude of this increase was reduced following a single dose of dapagliflozin or exenatide at baseline visit (average of 1.16±0.17 mM) but was further increased following a single dose in the dapagliflozin receiving groups at 12 weeks visit (average of 1.83±0.28 mM). Under acute testing conditions, single dose of dapagliflozin treatment was associated with reduced urinary BHB clearance at baseline and 12 weeks visits. After 12 weeks of treatment and under basal conditions, ketone levels in blood and urine were not significantly altered following dapagliflozin or Bydureon alone but were significantly higher in the triple therapy group (0.22±0. 04 to 0.42±0. 07 mM in blood). At 12 weeks of treatment, dapagliflozin was associated with increased glucagon and lipolysis (increased FFAs) while Bydureon was associated with decreased glucagon and lipolysis. During the 12 weeks there were no episode of DKA or hypoglycemia (&lt;55mg/dl).

Conclusions

Adjunct therapies treatment in T1DM results in significant improvements in glycemia and HbA1c. Dapagliflozin treatment increases lipolysis and glucagon while reduces urinary excretion of BHB. This may contribute to the increased blood ketone levels following extended treatment with dapagliflozin. However, the magnitude of this increase in ketones is significantly below DKA ketones levels which indicates that other DKA triggering factors play a more significant role.

Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Efficacy of lower doses of pioglitazone after stroke or transient ischaemic attack in patients with insulin resistance

AIMS

Pioglitazone is a potent insulin-sensitizing drug with anti-atherosclerotic properties, but adverse effects have limited its use. We assessed the benefits and risks of lower versus higher doses of pioglitazone taken by participants in the Insulin Resistance Intervention in Stroke Trial.

MATERIALS AND METHODS

Efficacy [myocardial infarction (MI) or recurrent stroke] new-onset diabetes) and adverse outcomes (oedema, weight gain, heart failure and bone fracture) were examined for subjects assigned to pioglitazone or placebo within strata defined by mode dose of study drug taken (i.e. the dose taken on most days in the study).

RESULTS

Among the 1938 patients randomized to pioglitazone, the mode dose was <15 mg/day in 546 participants, 15 mg/day in 128, 30 mg/day in 89, and 45 mg/day in 1175. There was no significant effect on stroke/MI or new-onset diabetes with <15 mg/day. For 15 mg/30 mg/day pooled, the adjusted hazard ratios (95% CI) for stroke/MI were 0.48 (0.30, 0.76; p = .002) and 0.74 (0.69, 0.94) for 45 mg/day. For new-onset diabetes, the adjusted hazard ratios were 0.34 (0.15, 0.81; p = .001) and 0.31 (0.59, 0.94; p = .001) respectively. For oedema, weight gain and heart failure, the risk estimates for pioglitazone were lower for subjects taking <45 mg daily. For fractures, the increased risk with pioglitazone was similar across all dose strata.

CONCLUSIONS

Lower doses of pioglitazone appear to confer much of the benefit with less adverse effects than the full dose. Further study is needed to confirm these findings so that clinicians may optimize dosing of this secondary prevention strategy in patients with stroke.

High prevalence of subnormal testosterone in obese adolescent males: reversal with bariatric surgery

OBJECTIVE

Obesity in adolescent males is associated with the lowering of total and free testosterone concentrations. Weight loss may increase testosterone concentrations.

DESIGN AND METHODS

We evaluated the changes in sex hormones following bariatric surgery in 34 males (age range: 14.6-19.8 years) with obesity. These participants were part of a prospective multicenter study, Teen-Longitudinal Assessment of Bariatric Surgery. The participants were followed up for 5 years after surgery. Total testosterone, total estradiol, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, C-reactive protein, insulin and glucose were measured at baseline, 6 months and annually thereafter. Free testosterone, free estradiol and HOMA2-IR were calculated.

RESULTS

Study participants lost one-third of their body weight after bariatric surgery, with maximum weight loss achieved at 24 months for most participants. Free testosterone increased from 0.17 (95% CI: 0.13 to 0.20) at baseline to 0.34 (95% CI: 0.30 to 0.38) and 0.27 nmol/L (95% CI: 0.23 to 0.32) at 2 and 5 years (P < 0.001 for both), respectively. Total testosterone increased from 6.7 (95% CI: 4.7 to 8.8) at baseline to 17.6 (95% CI: 15.3 to 19.9) and 13.8 (95% CI: 11.0 to 16.5) nmol/L at 2 and 5 years (P < 0.001), respectively. Prior to surgery, 73% of the participants had subnormal free testosterone (<0.23 nmol/L). After 2 and 5 years, only 20 and 33%, respectively, had subnormal free testosterone concentrations. Weight regain was related to a fall in free testosterone concentrations.

CONCLUSIONS

Bariatric surgery led to a robust increase in testosterone concentrations in adolescent males with severe obesity. Participants who regained weight had a decline in their testosterone concentrations.

4-Phenylbutyric acid improves free fatty acid-induced hepatic insulin resistance in vivo

Plasma free fatty acids (FFAs) are elevated in obesity and can induce insulin resistance via endoplasmic reticulum (ER) stress. However, it is unknown whether hepatic insulin resistance caused by the elevation of plasma FFAs is alleviated by chemical chaperones. Rats received one of the following i.v. treatments for 48 h: saline, intralipid plus heparin (IH), IH plus the chemical chaperone 4-phenylbutyric acid (PBA), or PBA alone and a hyperinsulinemic-euglycemic clamp was performed during the last 2 h. PBA co-infusion normalized IH-induced peripheral insulin resistance, similar to our previous findings with an antioxidant and an IκBα kinase β (IKKβ) inhibitor. Different from our previous results with the antioxidant and IKKβ inhibitor, PBA also improved IH-induced hepatic insulin resistance in parallel with activation of Akt. Unexpectedly, IH did not induce markers of ER stress in the liver, but PBA prevented IH-induced elevation of phosphorylated eukaryotic initiation factor-2α protein in adipose tissue. PBA tended to decrease circulating fetuin-A and significantly increased circulating fibroblast growth factor 21 (FGF21) without affecting markers of activation of hepatic protein kinase C-δ or p38 mitogen-activated protein kinase that we have previously involved in hepatic insulin resistance in this model. In conclusion: (i) PBA prevented hepatic insulin resistance caused by prolonged plasma FFA elevation without affecting hepatic ER stress markers; (ii) the PBA effect is likely due to increased FGF21 and/or decreased fetuin-A, which directly signal to upregulate Akt activation.

Dapagliflozin reduces systolic blood pressure and modulates vasoactive factors

AIM

To investigate the mechanisms underlying improvements in blood pressure (BP) and congestive heart failure outcomes following treatment with dapagliflozin, a sodium-glucose co-transporter-2 inhibitor.

RESEARCH DESIGN AND METHODS

A total of 52 patients with type 2 diabetes (T2D) with an HbA1c of less than 8% participated in this prospective, double-blind and placebo-controlled study. Patients were randomized (1:1) to either dapagliflozin 10 mg daily or placebo for 12 weeks. Half the patients were also monitored for 6 h following their first dose for acute effects on BP. Blood and urine samples were collected and levels of angiotensinogen, angiotensin II, renin, aldosterone, endothelin-1, atrial natriuretic peptide (ANP), brain natriuretic peptide, cyclic adenosine monophosphate, cyclic guanosine monophosphate (cGMP) and neprilysin were measured. The expression of angiotensin-converting enzyme, guanylate cyclase and phosphodiesterase 5 (PDE5) was measured in circulating mononuclear cells (MNC).

RESULTS

A total of 24 and 23 patients receiving dapagliflozin and placebo, respectively, completed the 12-week study. Systolic BP decreased significantly, compared with placebo, both after single-dose (by 7 ± 3 mmHg) and 12-week (by 7 ± 2 mmHg) treatment with dapagliflozin. Dapagliflozin suppressed angiotensin II and angiotensinogen (by 10.5 ± 2.1 and 1.45 ± 0.42 μg/mL, respectively) and increased ANP and cGMP (by 34 ± 11 and 29 ± 11 pmol/mL, respectively) compared with the placebo group. cGMP levels also increased acutely following a single dose of dapagliflozin. Dapagliflozin also suppressed PDE5 expression by 26% ± 11% in MNC. There were no changes observed in the other vasoactive mediators investigated.

CONCLUSIONS

Dapagliflozin administration in T2D resulted in both acute and chronic reduction in systolic BP, a reduction in vasoconstrictors and an increase in vasodilators. These changes may potentially contribute to its antihypertensive effects and its benefits in congestive cardiac failure.

The Story of a Radiologically Undetectable, Testosterone Producing Leydig Cell Tumor

Introduction: Leydig stromal cell tumors are uncommon ovarian tumors that produce testosterone leading to hyperandrogenism. We present a case of a 63 year old lady with significantly elevated testosterone levels that did not have clear ovaries visualized on imaging, but was subsequently found to have a Leydig cell tumor on pathology after ovarian resection.

Clinical Case: A 63 year old female with a past medical history of COPD, hypothyroidism, hyperlipidemia, hypertension and uterine fibroids status post hysterectomy and left oophorectomy in 1995 was referred to endocrinology for hirsutism. The patient reported first noticing abnormal hair growth approximately one year prior to presentation having developed increasingly coarse and thick facial hair, abdominal wall hair, and chest hair. On physical examination, she was noted to have coarse hair across her upper lip and chin continuous along the jawline along with fine, dark hair diffusely across her anterior abdomen. Initial laboratory cell evaluation revealed total testosterone 378 ng/dL, free testosterone 53ng/dL, DHEAS 64 ug/dL. Repeat labs drawn three months later confirmed the markedly elevated total testosterone of 362 ng/dL and free testosterone 44.2 ng/dL, concentrations normally seen in males. A CT scan of the abdomen and pelvis was done and did not reveal any masses. In addition, no ovaries were appreciated on imaging. A transvaginal ultrasound also did not reveal any clear ovaries. The patient ended up undergoing a right oophorectomy. Histological examination was consistent with a Leydig cell tumor. Following oophorectomy, her testosterone concentrations normalized (5ng/dL) and hirsutism began to regress.

Clinical Lesson: Hyperandrogenism in women is typically classified into non-tumorous and tumorous. The differential for non-tumorous hyperandrogenism includes PCOS, congenital adrenal hyperplasia (CAH), and ovarian hyperthecosis. Tumorous causes include ovarian tumors such as Sertoli-Leydig cell tumors, hilus cell tumors, and theca cell tumors. Adrenal tumors secreting testosterone are extremely rare. Often with these tumors, there is significantly increased testosterone levels (&gt; 140ng/dL) and rapid progression of symptoms. Sex cord stromal tumors account for only 5-8% of all ovarian tumors with Leydig stromal tumors a rare group that accounts for less than 0.1% of all ovarian tumors. The tumors are functional producing testosterone leading to marked hyperandrogenism and virilization. They are also usually benign and unilateral. This patient had hyperandrogenism manifested by hirsutism with markedly elevated testosterone concentrations. In addition, this case is unique in that a CT scan and transvaginal ultrasound did not clearly demonstrate her right ovary. Despite having a normal appearing right ovary during surgery, patient was found to have Leydig cell tumor following histological examination.

The side effects of immune checkpoint inhibitor therapy on the endocrine system

Immune checkpoint inhibitors (ICIs) are a relatively newer class of drugs approved for the treatment of malignancies such as melanoma, renal, bladder and lung cancer. Immune-related adverse events (IrAEs) involving the endocrine system are a common side effect of these drugs. The spectrum of endocrine adverse events varies by the drug class. Cytotoxic T-lymphocyte–associated antigen-4 inhibitors commonly cause hypophysitis/hypopituitarism, whereas the incidence of thyroid disease is higher with programmed cell death (PD)-1/ ligand (PD-L) protein 1 inhibitors. The focus of this review is to describe the individual endocrinopathies with their possible mechanisms, signs and symptoms, clinical assessment and disease management. Multiple mechanisms of IrAEs have been described in literature including type II/IV hypersensitivity reactions and development of autoantibodies. Patients with pre-existing autoimmune endocrine diseases can have disease exacerbation following ICI therapy rather than de novo IrAEs. Most of the endocrinopathies are relatively mild, and timely hormone replacement therapy allows continuation of ICIs. However, involvement of the pituitary–adrenal axis could be life-threatening if not recognized. Corticosteroids are helpful when the pituitary–adrenal axis is involved. In cases of severe endocrine toxicity (grade 3/4), ICIs should be temporarily discontinued and can be restarted after adequate hormonal therapy. Endocrinologists and general internists need to be vigilant and maintain a high degree of awareness for these adverse events.

Long-term efficacy and safety of dapagliflozin in patients with inadequately controlled type 1 diabetes: pooled 52-week outcomes from the DEPICT-1 and -2 studies

AIM

To evaluate the efficacy and safety of adjunct dapagliflozin therapy in patients with type 1 diabetes (T1D).

MATERIALS AND METHODS

DEPICT-1 and -2 were randomized, double-blind, parallel-group, 24-week studies, with 28-week extension periods. Adults with T1D and HbA1c 7.5%-10.5% were randomized (1:1:1) to receive dapagliflozin 5 mg, 10 mg or placebo. The short- and long-term efficacy and safety of dapagliflozin were examined in an exploratory pooled analysis of both studies.

RESULTS

Efficacy analyses included 530, 529 and 532 and safety analysis included 548, 566 and 532 patients in the dapagliflozin 5 mg, 10 mg and placebo groups, respectively. Baseline characteristics were similar between treatment groups. At week 24, reductions were seen with dapagliflozin 5 and 10 mg compared with placebo in HbA1c (-0.40%, -0.43% vs. 0.00%) and body weight (-2.45, -2.91 vs. 0.11 kg). HbA1c and body weight reductions versus placebo were also seen after 52 weeks of treatment. There was no imbalance in occurrence of severe hypoglycaemic events between groups. The proportion of patients experiencing definite diabetic ketoacidosis (DKA) was higher with dapagliflozin 5 mg (4.0%) and 10 mg (3.5%) compared with placebo (1.1%) over 52 weeks; most events were of mild or moderate severity, and all resolved with treatment.

CONCLUSIONS

Over 52 weeks, dapagliflozin provided glycaemic and weight benefits, with no increased frequency of severe hypoglycaemia compared with placebo. More DKA events were reported with dapagliflozin than placebo, highlighting the importance of appropriate patient selection, education and risk-mitigation strategies.

Mechanisms underlying the metabolic actions of testosterone in humans: A narrative review

The role of testosterone in improving sexual symptoms in men with hypogonadism is well known. However, recent studies indicate that testosterone plays an important role in several metabolic functions in males. Multiple PubMed searches were conducted with the use of the terms testosterone, insulin sensitivity, obesity, type 2 diabetes, anaemia, bone density, osteoporosis, fat mass, lean mass and body composition. This narrative review is focused on detailing the mechanisms that underlie the metabolic aspects of testosterone therapy in humans. Testosterone enhances insulin sensitivity in obese men with hypogonadism by decreasing fat mass, increasing lean mass, decreasing free fatty acids and suppressing inflammation. At a cellular level, testosterone increases the expression of insulin receptor β subunit, insulin receptor substrate-1, protein kinase B and glucose transporter type 4 in adipose tissue and adenosine 5'-monophosphate-activated protein kinase expression and activity in skeletal muscle. Observational studies show that long-term therapy with testosterone prevents progression from prediabetes to diabetes and improves HbA1c. Testosterone increases skeletal muscle satellite cell activator, fibroblast growth factor-2 and decreases expression of the muscle growth suppressors, myostatin and myogenic regulatory factor 4. Testosterone increases haematocrit by suppressing hepcidin and increasing expression of ferroportin along with that of transferrin receptor and plasma transferrin concentrations. Testosterone also increases serum osteocalcin concentrations, which may account for its anabolic actions on bone. In conclusion, testosterone exerts a series of potent metabolic effects, which include insulin sensitization, maintenance and growth of the skeletal muscle, suppression of adipose tissue growth and maintenance of erythropoiesis and haematocrit.

Benefit/risk profile of dapagliflozin 5 mg in the DEPICT-1 and -2 trials in individuals with type 1 diabetes and body mass index ≥27 kg/m2

AIM

The DEPICT-1 and -2 studies (NCT02268214, NCT02460978) evaluated the efficacy and safety of dapagliflozin in individuals with type 1 diabetes who were receiving intensive insulin therapy. The DEPICT-1 and -2 studies (NCT02268214, NCT02460978) evaluated the efficacy and safety of dapagliflozin in individuals with type 1 diabetes. This post-hoc study investigated the safety and efficacy of dapagliflozin in individuals with BMI ≥27 kg/m² to assess if the benefit/risk ratio associated with dapagliflozin treatment can be further improved than that observed in the overall DEPICT population.

METHODS

Changes in glycated haemoglobin (HbA1c) and body weight, percentage change in daily insulin dose and proportion of participants achieving HbA1c reduction ≥0.5% without severe hypoglycaemia were evaluated at weeks 24 and 52. Changes in mean interstitial glucose, mean amplitude of glycaemic excursions and time in target glycaemic range were evaluated at week 24. Safety was assessed until week 56.

RESULTS

Week-52 adjusted mean (SE) change from baseline for HbA1c was -0.26% (0.05) with dapagliflozin versus +0.08% (0.05) with placebo and for body weight was -2.74 kg (0.25) with dapagliflozin versus +0.81 kg (0.26) with placebo. Mean (SE) percentage change in daily insulin dose was -10.5% (1.23) with dapagliflozin versus -1.4% (1.36) with placebo. Time spent in target glycaemic range increased by 2.2 h/day versus placebo. Dapagliflozin was well tolerated, with fewer participants experiencing diabetic ketoacidosis (dapagliflozin, 1.7%; placebo, 1.0%) than dapagliflozin 5 mg receiving participants in the pooled DEPICT populations.

CONCLUSIONS

Compared with the pooled DEPICT population, the benefit/risk profile of adjunct dapagliflozin therapy was more favourable in individuals with type 1 diabetes with body mass index ≥27 kg/m² because of the reduced risk of diabetic ketoacidosis in this population.

Remission of type 2 diabetes following long-term treatment with injectable testosterone undecanoate in patients with hypogonadism and type 2 diabetes: 11-year data from a real-world registry study

AIMS

To investigate whether testosterone therapy (TTh) in men with hypogonadism and type 2 diabetes mellitus (T2DM) improves glycaemic control and insulin sensitivity, and results in remission of T2DM.

MATERIAL AND METHODS

A total of 356 men who had total testosterone levels ≤12.1 nmol/L (350 ng/dL) and symptoms of hypogonadism were included in the study and followed up for 11 years. All patients received standard diabetes treatment and 178 patients additionally received parenteral testosterone undecanoate 1000 mg every 12 weeks following an initial 6-week interval. A control group comprised 178 hypogonadal patients who opted not to receive TTh.

RESULTS

Patients with hypogonadism and T2DM treated with testosterone had significant progressive and sustained reductions in fasting glucose, glycated haemoglobin (HbA1c) and fasting insulin over the treatment period. In the control group, fasting glucose, HbA1c and fasting insulin increased. Among the patients treated with testosterone 34.3% achieved remission of their diabetes and 46.6% of patients achieved normal glucose regulation. Of the testosterone-treated group, 83.1% reached the HbA1c target of 47.5 mmol/mol (6.5%) and 90% achieved the HbA1c target of 53.0 mmol/mol (7%). In contrast, no remission of diabetes or reductions in glucose or HbA1c levels were noted in the control group. There were fewer deaths, myocardial infarctions, strokes and diabetic complications in the testosterone-treated group.

CONCLUSIONS

Long-term TTh in men with T2DM and hypogonadism improves glycaemic control and insulin resistance. Remission of diabetes occurred in one-third of the patients. TTh is potentially a novel additional therapy for men with T2DM and hypogonadism.

Liraglutide treatment in overweight and obese patients with type 1 diabetes: A 26-week randomized controlled trial; mechanisms of weight loss

AIM

To investigate the effects of liraglutide treatment on glycaemic control and adipose tissue metabolism in overweight and obese people with type 1 diabetes (T1DM).

RESEARCH DESIGN AND METHODS

A total of 84 adult overweight and obese patients with T1DM, with no detectable C-peptide, were randomized (1:1) to either placebo or 1.8 mg/d liraglutide for 6 months. Blood samples were collected at 0, 12 and 26 weeks. Subcutaneous adipose tissue biopsies, a high-calorie high-fat meal challenge test, continuous glucose monitoring, dual-energy X-ray absorptiometry and MRI were performed before and at the end of treatment.

RESULTS

In all, 37 and 27 patients who received liraglutide and placebo, respectively, completed the study. Glycated haemoglobin fell by 0.41 ± 0.18% (4.5±1.4 mmol/mol) from baseline after liraglutide treatment (P = 0.001), and by 0.29 ± 0.19% (3.1±2.0 mmol/mol) compared to placebo (P = 0.1). There was no increase in hypoglycaemia, while the time spent in normal glycaemia increased (P = 0.015) and time spent in hyperglycaemia decreased (P = 0.019). Body weight fell significantly in the liraglutide group, mostly in the form of fat mass loss (including visceral fat), with no change in lean mass. Systolic blood pressure (SBP) also fell after liraglutide treatment. Liraglutide also caused a significant increase in the expression of adipose tissue triglyceride lipase, carnitine palmitoyl transferase-1, peroxisome proliferator-activated receptor (PPAR)α, PPARδ, uncoupling protein-2 and type 2 iodothyronine deiodinase in the adipose tissue.

CONCLUSIONS

Liraglutide improves glycaemia, reduces adiposity and SBP. Liraglutide also stimulates mechanisms involved with an increase in lipid oxidation and thermogenesis, while conserving lean body mass.

Effect of dapagliflozin as an adjunct to insulin over 52 weeks in individuals with type 1 diabetes: post-hoc renal analysis of the DEPICT randomised controlled trials

BACKGROUND

The DEPICT-1 and DEPICT-2 studies showed that dapagliflozin as an adjunct to insulin in individuals with inadequately controlled type 1 diabetes improved glycaemic control and bodyweight, without increase in risk of hypoglycaemia. We aimed to determine the effect of dapagliflozin on urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) using pooled data from the DEPICT studies.

METHODS

In this post-hoc analysis, we used data pooled from both DEPICT studies (DEPICT-1 ran from Nov 11, 2014, to Aug 25, 2017; DEPICT-2 ran from July 8, 2015, to April 18, 2018), in which participants were aged 18-75 years, with inadequately controlled type 1 diabetes and with a baseline UACR of at least 30 mg/g. In the DEPICT studies, participants were randomly assigned (1:1:1) to receive dapagliflozin (5 mg or 10 mg) or placebo all plus insulin, for 24 weeks, with a 28-week long-term extension (ie, 52 weeks in total). In this post-hoc analysis, we assessed the percentage change from baseline in UACR and in eGFR, up to 52 weeks. UACR, eGFR, and safety were assessed in all eligible participants who had received at least one dose of study drug. HbA_1c, bodyweight, and systolic blood pressure were assessed in all participants who received at least one dose of study drug during the first 24-week period, and who had a baseline and any post-baseline assessment for that parameter. The DEPICT trials were registered with ClinicalTrials.gov, NCT02268214 (DEPICT-1), NCT02460978 (DEPICT-2), and are now complete.

RESULTS

251 participants with albuminuria at baseline were included in this post-hoc analysis; of whom 80 (32%) had been randomly assigned to dapagliflozin 5 mg, 84 (33%) to dapagliflozin 10 mg, and 87 (35%) to placebo. Compared with placebo, treatment with both dapagliflozin doses improved UACR over 52 weeks. At week 52, mean difference in change from baseline versus placebo in UACR was -13·3% (95% CI -37·2 to 19·8) for dapagliflozin 5 mg and -31·1% (-49·9 to -5·2) for dapagliflozin 10 mg. No notable change from baseline was seen in eGFR, with a mean difference in change from baseline versus placebo of 3·27 mL/min per 1·73 m² (95% CI -0·92 to 7·45) for dapagliflozin 5 mg and 2·12 mL/min per 1·73 m² (-2·03 to 6·27) for dapagliflozin 10 mg. Similar proportions of participants in each treatment group had adverse events and serious adverse events, including hypoglycaemia and diabetic ketoacidosis; no new safety signals were identified in this population.

INTERPRETATION

Treatment with dapagliflozin resulted in UACR reduction, which might provide renoprotective benefits in individuals with type 1 diabetes and albuminuria. Dedicated prospective studies are needed to confirm these findings as prespecified endpoints.

FUNDING

AstraZeneca.

Adjunct therapies in treatment of type 1 diabetes

In spite of developments with novel insulin preparations, novel modes of insulin delivery with insulin infusion pumps, and the facility of continuous glucose monitoring, only 20% of patients with type 1 diabetes are under adequate control. The need for innovation is clear, and, therefore, the use of adjunct therapies with other pharmacological agents currently in use for type 2 diabetes, has been tried. Currently, pramlintide is the only agent licensed for use in this condition in addition to insulin. Global trials have been conducted with liraglutide, a glucagon-like peptide 1 receptor agonist (GLP-1RA), dapagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, and sotagliflozin, an inhibitor of both SGLT1 and SGLT2 transporters. While dapagliflozin and sotagliflozin have now been licensed for clinical use in this condition in Europe and Japan, they have hitherto not been licensed in the United States due to a small increase in the risk of diabetic ketoacidosis. However, these agents reduce glycosylated hemoglobin (HbA1c) by 0.4%, reduce glycemic oscillations, and do not increase the risk of hypoglycemia. Liraglutide, on the other hand, induced a smaller reduction in HbA1c and thus was not considered for a license. However, further trials are currently being conducted with a combination of semaglutide, the most potent GLP-1RA, and dapagliflozin to determine whether this approach would yield better outcomes.