Decreased pituitary-gonadal secretion in men with obstructive sleep apnea

Decreased libido is frequently reported in male patients with obstructive sleep apnea (OSA). The decline in morning serum testosterone levels previously reported in these patients was within the normal adult male range and does not explain the frequent association of OSA and sexual dysfunction. We determined serum LH and testosterone levels every 20 min between 2200-0700 h with simultaneous sleep recordings in 10 men with sleep apnea and in 5 normal men free of any breathing disorder in sleep. The mean levels and area under the curve of LH and testosterone were significantly lower in OSA patients compared with controls [LH, 24.9 +/- 10.2 IU/liter.h vs. 43.4 +/- 9.5 (P < 0.005); testosterone, 67.2 +/- 11.5 nmol/liter.h vs. 113.3 +/- 26.8 (P < 0.003)]. Four of 10 patients had hypogonadal morning (0700 h) serum testosterone levels. Analysis of covariance (ANCOVA) revealed that the 2 groups differed significantly in the amount of LH and testosterone secreted at night independent of age or degree of obesity. After partialing out body mass index, there was a significant negative correlation between the amounts of LH and testosterone secreted at night and the respiratory distress index, but not with degree of hypoxia. Our findings suggest that OSA in men is associated with dysfunction of the pituitary-gonadal axis. The relation between LH-testosterone profiles and the severity of OSA suggests that sleep fragmentation and, to a lesser extent, hypoxia in addition to the degree of obesity and aging may be responsible for the central suppression of testosterone in these patients.     

Glucose homeostasis and safety in patients with acromegaly converted from long-acting octreotide to pegvisomant

CONTEXT: In clinical practice, patients with acromegaly may be switched from therapy with long-acting somatostatin analogs to pegvisomant. The effect of changing therapies on glucose homeostasis and safety has not been reported. OBJECTIVES: The objectives of this study were to monitor changes in IGF-I levels, glycemic control, and safety, particularly liver function and tumor size. DESIGN: This was a multicenter, open-label, 32-wk trial study. SETTING: The study was performed at outpatient clinics. PATIENTS: Fifty-three patients with acromegaly previously treated with octreotide long-acting release (LAR) participated in this study. Intervention: Pegvisomant (10 mg/d) was initiated 4 wk after the last dose of octreotide LAR and was adjusted based on serum IGF-I concentrations at wk 12, 20, and 28. MAIN OUTCOME MEASURES: The main outcome measures were changes in IGF-I, glycosylated hemoglobin A1c (HbA1c), fasting plasma glucose, and safety during the first 12 wk after conversion. RESULTS: At the end of pegvisomant treatment, IGF-I was normalized in 78% of patients. At wk 32, median fasting glucose concentration and HbA1c were reduced (-1.4 mmol/liter and -0.4%, respectively; both P < or = 0.0001) in the study population. Improvements in glycemic control occurred in patients with normal IGF-I concentrations at wk 4 [n = 15; fasting glucose, -1.7 mmol/liter (P < or = 0.0001); HbA1c -0.2% (P = 0.03)]. Decreases in fasting glucose and HbA1c levels were observed in patients with and without diabetes. HbA1c was reduced by more than 1.0% in patients with diabetes. Median pituitary tumor volume did not change, although tumor volume increased in two patients with macroadenomas. CONCLUSIONS: Conversion from octreotide LAR to pegvisomant was safe and well tolerated. Improved glycemic control indicates that pegvisomant should be considered in patients with acromegaly and diabetes.     

Icosapent Ethyl for Primary Versus Secondary Prevention of Major Adverse Cardiovascular Events in Hypertriglyceridemia: Value for Money Analysis

BackgroundIcosapent ethyl (IPE) is approved for the prevention of major adverse cardiovascular events (MACE) in patients with hypertriglyceridemia. However, due to budget constraints, access to IPE will inevitably be limited to a fraction of eligible patients. To help maximize value for money spent, we estimated the number of preventable MACE when providing IPE for primary versus secondary prevention.MethodsThe number of preventable MACE was estimated by dividing the available budget by the cost needed to treat (CNT) to prevent one MACE. CNT was calculated as the product of the number needed to treat (NNT) to prevent 1 MACE by therapy cost. NNT values were determined according to the Reduction of Cardiovascular Events with Icosapent Ethyl–Intervention Trial (REDUCE-IT) results. The budget limit was set as the United States’ threshold suggested by the Institute for Clinical and Economic Review. Sensitivity analysis was performed regarding the cost of IPE in the United States.ResultsThe NNT to prevent 1 MACE over 4.9 years in the Reduction of Cardiovascular Events with Icosapent Ethyl–Intervention Trial primary prevention cohort was 59 (95% confidence interval [CI]: 24-∞) versus 14 (11-21) for secondary prevention. At an annual IPE cost of $2915, the CNT to prevent 1 MACE was $842,726 (95% CI: $342,804-∞) and $199,969 ($157,118-$299,953) accordingly. A total of $819 million worth of IPE can avoid 4762 MACE (95% CI: 0-11,707) versus 20,069 (13,379-25,541), when provided as primary versus secondary prevention therapy; P < .001. The number of avoided MACE is sensitive to IPE price.ConclusionsPrioritizing IPE therapy for patients with an established cardiovascular disease may provide significantly more value for money than primary prevention.     

Reduced Insulin Sensitivity Is Related to Less Endogenous Dopamine at D2/3 Receptors in the Ventral Striatum of Healthy Nonobese Humans

Background:

Food addiction is a debated topic in neuroscience. Evidence suggests diabetes is related to reduced basal dopamine levels in the nucleus accumbens, similar to persons with drug addiction. It is unknown whether insulin sensitivity is related to endogenous dopamine levels in the ventral striatum of humans. We examined this using the agonist dopamine D_2/3 receptor radiotracer [¹¹C]-(+)-PHNO and an acute dopamine depletion challenge. In a separate sample of healthy persons, we examined whether dopamine depletion could alter insulin sensitivity.

Methods:

Insulin sensitivity was estimated for each subject from fasting plasma glucose and insulin using the Homeostasis Model Assessment II. Eleven healthy nonobese and nondiabetic persons (3 female) provided a baseline [¹¹C]-(+)-PHNO scan, 9 of which provided a scan under dopamine depletion, allowing estimates of endogenous dopamine at dopamine D_2/3 receptor. Dopamine depletion was achieved via alpha-methyl-para-tyrosine (64mg/kg, P.O.). In 25 healthy persons (9 female), fasting plasma and glucose was acquired before and after dopamine depletion.

Results:

Endogenous dopamine at ventral striatum dopamine D_2/3 receptor was positively correlated with insulin sensitivity (r(7)=.84, P=.005) and negatively correlated with insulin levels (r(7)=-.85, P=.004). Glucose levels were not correlated with endogenous dopamine at ventral striatum dopamine D_2/3 receptor (r(7)=-.49, P=.18). Consistently, acute dopamine depletion in healthy persons significantly decreased insulin sensitivity (t(24)=2.82, P=.01), increased insulin levels (t(24)=-2.62, P=.01), and did not change glucose levels (t(24)=-0.93, P=.36).

Conclusion:

In healthy individuals, diminished insulin sensitivity is related to less endogenous dopamine at dopamine D_2/3 receptor in the ventral striatum. Moreover, acute dopamine depletion reduces insulin sensitivity. These findings may have important implications for neuropsychiatric populations with metabolic abnormalities.     

Designing a Primary Care–Based Deprescribing Intervention for Patients with Dementia and Multiple Chronic Conditions: a Qualitative Study

BackgroundPatients with dementia and multiple chronic conditions (MCC) frequently experience polypharmacy, increasing their risk of adverse drug events.ObjectivesTo elucidate patient, family, and physician perspectives on medication discontinuation and recommended language for deprescribing discussions in order to inform an intervention to increase awareness of deprescribing among individuals with dementia and MCC, family caregivers and primary care physicians. We also explored participant views on culturally competent approaches to deprescribing.DesignQualitative approach based on semi-structured interviews with patients, caregivers, and physicians.ParticipantsPatients aged ≥ 65 years with claims-based diagnosis of dementia, ≥ 1 additional chronic condition, and ≥ 5 chronic medications were recruited from an integrated delivery system in Colorado and an academic medical center in Maryland. We included caregivers when present or if patients were unable to participate due to severe cognitive impairment. Physicians were recruited within the same systems and through snowball sampling, targeting areas with large African American and Hispanic populations.ApproachWe used constant comparison to identify and compare themes between patients, caregivers, and physicians.Key ResultsWe conducted interviews with 17 patients, 16 caregivers, and 16 physicians. All groups said it was important to earn trust before deprescribing, frame deprescribing as routine and positive, align deprescribing with goals of dementia care, and respect caregivers’ expertise. As in other areas of medicine, racial, ethnic, and language concordance was important to patients and caregivers from minority cultural backgrounds. Participants favored direct-to-patient educational materials, support from pharmacists and other team members, and close follow-up during deprescribing. Patients and caregivers favored language that explained deprescribing in terms of altered physiology with aging. Physicians desired communication tips addressing specific clinical situations.ConclusionsCulturally sensitive communication within a trusted patient-physician relationship supplemented by pharmacists, and language tailored to specific clinical situations may support deprescribing in primary care for patients with dementia and MCC.Electronic supplementary materialThe online version of this article (10.1007/s11606-020-06063-y) contains supplementary material, which is available to authorized users.KEY WORDS: deprescribing, patient-physician communication, dementia     

Effect of Matrix Metalloproteinase Inhibition by Doxycycline on Myocardial Healing and Remodeling after Myocardial Infarction

Summary The aim of conducting this study was to assess the clinical relevance of matrix metalloproteinase (MMP) inhibition by doxycycline, an effective MMP inhibitor, in a rat model of extensive myocardial infarction (MI) and left ventricular (LV) dysfunction. Rats (n = 22) were subjected to extensive anterior MI. Doxycycline (25 mg SC, daily) or saline (control) injections were started for nine days thereafter. The effect of doxycycline on MMP activity in the infarcted and remote myocardium was measured by zymography, in another subgroup (n = 8), nine days after MI. Echocardiography and magnetic resonance imaging (MRI) studies were performed at one and thirty days after MI to assess LV remodeling and function. After 4 weeks, hearts were fixed, and subjected to morphometric and histological analysis. Compared with control, doxycycline treatment attenuated MMP-9 and -2 activity in both infarcted and remote myocardium. Serial echocardiography studies showed that doxycycline failed to attenuate scar thinning, LV dilatation and dysfunction. MRI study showed that doxycycline impaired LV compensatory hypertrophy. Furthermore, compared with control, doxycycline reduced vessel density (/mm² ± SEM) in the infarcted myocardium (84 ± 16 vs. 46 ± 9/mm², respectively; p < 0.05). Our work suggest that effective MMPs’ inhibition in the infarcted and remote myocardium by doxycycline does not prevent LV remodeling and dysfunction but impairs angiogenesis and compensatory LV hypertrophy. Our findings caution against aggressive, non-selective inhibition of MMPs in the early healing phase after MI.     

Inhibitor design by wrapping packing defects in HIV-1 proteins

Two viral proteins, HIV-1 protease and HIV-1 integrase, have been targeted for inhibitor design to prevent assembly and maturation of HIV-1 virions. The enzymatic mechanism of these proteins involves side-chain groups that serve as general acids or bases. Furthermore, catalytic activity requires that water be removed from the microenvironment surrounding the chemical reaction site or be constrained to serve as an activated nucleophile. Here, we identify previously unrecognized structural features that promote water removal from polar catalytic regions. Packing defects in the form of hydrogen bonds that are insufficiently dehydrated intramolecularly, named "dehydrons," are strategically placed in the structure to induce an anhydrous enzymatic pathway. Dehydrons become electrostatically enhanced and stabilized upon further desolvation. Thus, packing defects act synergistically with the polar active groups to enhance the enzymatic electrostatics. However, because dehydrons are sticky, they constitute targets for inhibitor design. We noticed that inhibitors attach to polar surfaces by further desolvating dehydrons, thus blocking the active sites or the sites involved in harnessing the substrate. The dehydrons are thus required for functional reasons, making them suitable targets. The differences in success when targeting HIV-1 protease, feline immunodeficiency virus protease, and HIV-1 integrase are rationalized in terms of the dehydron distribution, revealing possible improvements in the targeting strategy. Principles of design optimization are proposed to create an inhibitor that can be neutralized only at the expense of the loss of catalytic function. The possibility of using drugs that wrap dehydrons to block protein-protein associations is also discussed.