Association of low testosterone with changes in non-cardiovascular biomarkers in adult men

Testosterone has effects on many organs and systems. The purpose of this study was to test the hypothesis that low testosterone is associated with changes in various non-cardiovascular biomarkers in men older than 40 who were tested for possible hypogonadism. We extracted data from 9939 outpatient men who were over 40 years old (median age 56) and who also had concurrent laboratory measurements of total testosterone and one or more biomarkers of interest: estradiol, uric acid, prostate-specific antigen (PSA), sex-hormone binding globulin (SHBG), luteinizing hormone, creatinine, bone alkaline phosphatase (BAP), creatine kinase, hemoglobin A1c, and 25-hydroxy-vitamin D, and body mass index (BMI). In a smaller exploratory study of 19 otherwise healthy men presenting for evaluation of possible hypogonadism, pre-albumin (a.k.a.transthyretin, a marker of anabolism) and testosterone were measured. Men with lower levels of testosterone had significantly (p < 0.001) lower mean levels of PSA, SHBG, luteinizing hormone, and estradiol. Overall, men with low levels of testosterone also had significantly (p < 0.001) higher mean levels of LDH and BAP, but these associations varied between men who were younger or older than 56 years. There was a moderate but statistically significant positive correlation (r = 0.63, p < 0.05) between testosterone levels and pre-albumin. These results confirm our hypothesis that testosterone deficiency is associated with a broad range of systemic changes demonstrable in hormonal and non-hormonal serum assays in men over 40 years old being tested for possible hypogonadism.

Hematological Parameters Outperform Plasma Markers in Predicting Long-Term Mortality After Coronary Angiography

High-sensitivity troponin I (hsTnI) and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) are predictors of coronary artery disease. Recently, routine hematological parameters emerged as mortality predictors. We examined the predictive value of hematological parameters (from the Utrecht Patient Oriented Database) and hsTnI and NT-pro-BNP for mortality in a coronary angiography population (Utrecht Coronary Biobank n = 1913). Using Cox regression, receiver operating characteristics, integrated discrimination improvement (IDI), and continuous net reclassification improvement (cNRI) analysis, we compared the predictive properties of hematological parameters with hsTnI and NT-pro-BNP for mortality. During a median follow-up duration of 1.8 years, 77 deaths occurred. A panel of 7 hematological parameters (leukocyte count, reticulocyte mean corpuscular hemoglobin concentration, red blood cell [RBC] green (FL1) fluorescence, %neutrophils, %large [>120 fL] RBCs, %monocytes, and coefficient of variation of neutrophil complexity) was highly predictive. Added to clinical characteristics, hematological parameters (area under the curve [AUC]: 0.855, P < .001; IDI: 0.04, P = .02; cNRI: 0.41, P < .001) were better predictors than hsTnI (AUC: 0.818) or NT-pro-BNP (AUC: 0.834) alone or combined (AUC: 0.834). Hematological parameters may provide mortality risk information following coronary angiography and may be superior to hsTnI and/or NT-pro-BNP.

Impact of varying outcomes and definitions of suicidality on the associations of antiepileptic drugs and suicidality: comparisons from UK Clinical Practice Research Datalink (CPRD) and Danish national registries (DNR)

PURPOSE

The purpose of this study is to quantify the impact of the different outcomes and definitions of suicidality on the association between antiepileptic drugs (AEDs) and suicidality.

METHODS

Retrospective cohort studies of selected AEDs (carbamazepine, gabapentin, lamotrigine, phenytoin, pregabalin, topiramate and valproate) using data from UK Clinical Practice Research Datalink (CPRD) alone and linked to UK Hospital Episode Statistics (HES) and UK Office of National Statistics (ONS), and from Danish national registries (DNR). Follow-up started at initiation of one of the study AEDs, divided into exposure periods, a maximum 90-day post-exposure period, and the reference period starting the day after the 90-day post-exposure period ended. Primary outcomes were completed suicide (SUI)/suicide attempt (SA) for CPRD and SUI/deliberate self-harm (DSH) for DNR. We applied adjusted Cox regression analyses and sensitivity analyses with varying outcome definitions.

RESULTS

We analyzed 84,524 AED users from CPRD-HES-ONS (1188 SUI/SA; 96 SUI) and 258,180 users from DNR (7561 SUI/DSH; 781 SUI). The adjusted hazard ratios (HRs) on SUI/SA ranged between 1.3 (95% confidence interval (CI): 0.84-2.00) for lamotrigine and 2.7 (1.24-5.81) for phenytoin in CPRD-HES-ONS, and between 0.9 (0.78-1.00) for valproate and 1.8 (1.10-3.07) for phenytoin on SUI/DSH in DNR. HRs for the primary outcomes varied consistently across exposure periods and data sources. HRs for SUI were in general lower, more stable and similar for periods of exposure and the 90-day post-exposure period.

CONCLUSION

Applying different outcomes and definitions of suicidality had an impact on the relative risks of suicidality associated with the investigated AEDs with results for SUI being most consistent and reliable.

Prevalence of antibiotic use: a comparison across various European health care data sources

Purpose

There is widespread concern about increases in antibiotic use, but comparative data from different European countries on rates of use are lacking. This study was designed to measure and understand the variation in antibiotic utilization across five European countries.

Methods

Seven European healthcare databases with access to primary care data from Denmark, Germany, the Netherlands, Spain and the UK were used to measure and compare the point and 1‐year‐period prevalence of antibiotic use between 2004 and 2009. Descriptive analyses were stratified by gender, age and type of antibiotic. Separate analyses were performed to measure the most common underlying indications leading to the prescription of an antibiotic.

Results

The average yearly period prevalence of antibiotic use varied from 15 (Netherlands) to 30 (Spain) users per 100 patients. A higher prevalence of antibiotic use by female patients, the very young (0–9 years) and old (80+ years), was observed in all databases. The lowest point prevalence was recorded in June and September and ranged from 0.51 (Netherlands) to 1.47 (UK) per 100 patients per day. Twelve percent (Netherlands) to forty‐nine (Spain) percent of all users were diagnosed with a respiratory tract infection, and the most common type of antibiotic prescribed were penicillin.

Conclusion

Using identical methodology in seven EU databases to assess antibiotic use allowed us to compare drug usage patterns across Europe. Our results contribute quantitatively to the true understanding of similarities and differences in the use of antibiotic agents in different EU countries. © 2015 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons, Ltd.

Do case-only designs yield consistent results across design and different databases? A case study of hip fractures and benzodiazepines

Background

The case‐crossover (CXO) and self‐controlled case series (SCCS) designs are increasingly used in pharmacoepidemiology. In both, relative risk estimates are obtained within persons, implicitly controlling for time‐fixed confounding variables.

Objectives

To examine the consistency of relative risk estimates of hip/femur fractures (HFF) associated with the use of benzodiazepines (BZD) across case‐only designs in two databases (DBs), when a common protocol was applied.

Methods

CXO and SCCS studies were conducted in BIFAP (Spain) and CPRD (UK). Exposure to BZD was divided into non‐use, current, recent and past use. For CXO, odds ratios (OR; 95%CI) of current use versus non‐use/past were estimated using conditional logistic regression adjusted for co‐medications (AOR). For the SCCS, conditional Poisson regression was used to estimate incidence rate ratios (IRR; 95%CI) of current use versus non/past‐use, adjusted for age. To investigate possible event‐exposure dependence the relative risk in the 30 days prior to first BZD exposure was also evaluated.

Results

In the CXO current use of BZD was associated with an increased risk of HFF in both DBs, AOR_BIFAP = 1.47 (1.29–1.67) and AOR_CPRD = 1.55 (1.41–1.70). In the SCCS, IRRs for current exposure was 0.79 (0.72–0.86) in BIFAP and 1.21 (1.13–1.30) in CPRD. However, when we considered separately the 30‐day pre‐exposure period, the IRR for current period was 1.43 (1.31–1.57) in BIFAP and 1.37 (1.27–1.47) in CPRD.

Conclusions

CXO designs yielded consistent results across DBs, while initial SCCS analyses did not. Accounting for event‐exposure dependence, estimates derived from SCCS were more consistent across DBs and designs. © 2015 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

Genetic polymorphisms related to the renin-angiotensin-aldosterone system and response to antihypertensive drugs

IMPORTANCE OF THE FIELD

Only 23 - 41% of hypertensive patients receiving antihypertensive drugs achieve adequate blood pressure control. Multiple physiological systems regulate blood pressure and variation in genes involved in these systems may account for enhanced or diminished blood pressure lowering response to antihypertensive therapy.

AREAS COVERED IN THIS REVIEW

We explored explanations for variation in blood pressure response to antihypertensive drugs by linking genetic polymorphisms in renin-angiotensin-aldosterone system (RAAS) genes to antihypertensive drug response on intermediate parameters (e.g., potassium excretion, aldosterone levels). A MEDLINE search (1966 - 2008) was performed to identify publications reporting effects of genetic polymorphisms in the RAAS on antihypertensive drug response with regard to intermediate parameters.

WHAT THE READER WILL GAIN

With regard to the ACE insertion/deletion and the angiotensinogen -217G/A polymorphism variation in blood pressure response could be explained by effects on intermediate parameters. However, most studies that were identified with our search varied in study design, population and outcome, which complicate adequate comparisons.

TAKE HOME MESSAGE

Little evidence is available that explains these pharmacogenetic interactions. In the future, a better understanding of these mechanisms should provide a more solid evidence base for the individualized hypertension treatment based on genetic variation.