An explorative epigenome-wide association study of plasma renin and aldosterone concentration in a Ghanaian population: the RODAM study

BACKGROUND

The epigenetic regulation of the renin-angiotensin-aldosterone system (RAAS) potentially plays a role in the pathophysiology underlying the high burden of hypertension in sub-Saharan Africans (SSA). Here we report the first epigenome-wide association study (EWAS) of plasma renin and aldosterone concentrations and the aldosterone-to-renin ratio (ARR).

METHODS

Epigenome-wide DNA methylation was measured using the Illumina 450K array on whole blood samples of 68 Ghanaians. Differentially methylated positions (DMPs) were assessed for plasma renin concentration, aldosterone, and ARR using linear regression models adjusted for age, sex, body mass index, diabetes mellitus, hypertension, and technical covariates. Additionally, we extracted methylation loci previously associated with hypertension, kidney function, or that were annotated to RAAS-related genes and associated these with renin and aldosterone concentration.

RESULTS

We identified one DMP for renin, ten DMPs for aldosterone, and one DMP associated with ARR. Top DMPs were annotated to the PTPRN2, SKIL, and KCNT1 genes, which have been reported in relation to cardiometabolic risk factors, atherosclerosis, and sodium-potassium handling. Moreover, EWAS loci previously associated with hypertension, kidney function, or RAAS-related genes were also associated with renin, aldosterone, and ARR.

CONCLUSION

In this first EWAS on RAAS hormones, we identified DMPs associated with renin, aldosterone, and ARR in a SSA population. These findings are a first step in understanding the role of DNA methylation in regulation of the RAAS in general and in a SSA population specifically. Replication and translational studies are needed to establish the role of these DMPs in the hypertension burden in SSA populations.

The Role of the Microbiome in Cancer and Therapy Efficacy: Focus on Lung Cancer

The microbiome is extremely important for human health; more recently its role in the context of cancer became clear. Microbial effects range from enhancing cancer immunity and cancer therapy efficacy, to promoting cancer progression and inhibiting treatment efficacy. These broad implications led researchers to investigate these specific interactions, as well as how modification of the microbiome can improve cancer survival and treatment efficacy. While these interactions are better established for cancers such as gastric cancer, they are far less understood in others. As non-small cell lung cancer (NSCLC) makes up the majority of lung cancer cases, and is among the top causes of cancer deaths worldwide, understanding the mechanisms by which the microbiome may impact progression and treatment is crucial to improve patient survival and treatment response. A literature review was conducted to reveal the crosslink between human microbiome and lung cancer. This includes immune priming, induction of pro- or anti-tumor response, and the local effects of intra-tumoral microbiota. Overall, this is a complex multifactorial relationship, and there are broad implications as to how this knowledge can improve cancer treatment. Solutions include manipulation of the microbiome using probiotics, bacterial vaccines and antibiotics. Bacteria biomarkers may also be used as a diagnostic tool.

Stereotactic radiotherapy for large solitary brain metastases

PURPOSE

To assess effectiveness and toxicity levels of stereotactic radiation therapy without whole brain radiation therapy in patients with solitary brain metastases larger than 3cm.

PATIENTS AND METHODS

Between June 2007 and March 2009, 12 patients received fractionated stereotactic radiation therapy and 24 patients underwent stereotactic radiosurgery. For the fractionated stereotactic radiation therapy group, 3×7.7Gy were delivered to the planning target volume (PTV); median volume and diameter were 29.4 cm(3) and 4.4cm, respectively. For the stereotactic radiosurgery group, 14Gy were delivered to the PTV; median volume and diameter were 15.6 cm(3) and 3.7cm, respectively.

RESULTS

Median follow-up was 218 days. For the fractionated stereotactic radiation therapy group, local control rates were 100% at 360 days and 64% at 720 days; for the stereotactic radiosurgery group, rates were 58% at 360 days and 48% at 720 days (P=0.06). Median survival time was 504 days for the fractionated stereotactic radiation therapy group and 164 days for the stereotactic radiosurgery group (P=0.049). Two cases of grade 2 toxicity were observed in the fractionated stereotactic radiation therapy group, and 6 cases of grade 1-2 toxicity, in the stereotactic radiosurgery group.

CONCLUSIONS

This study provides data to support that fractionated stereotactic radiation therapy without whole brain radiation therapy with a margin dose of 3 fractions of 7.7Gy for treatment of solitary large brain metastases is efficient and well-tolerated. Because of the significant improvement in overall survival, this schedule should be assessed in a randomized trial.

[Difficulties encountered and solutions found when implementing stereotactic radiotherapy of non-small cell lung cancer]

The aim of this paper is to describe the difficulties encountered when implementing stereotactic radiotherapy of non-small cell lung cancer (T1-T2, N0, M0) using a voluntary breath-hold technique. From 25/03/2010 to 22/02/2011, eight patients with a non-small cell lung cancer were selected for treatment. CT images were obtained with the patient maintaining breath-hold using a spirometer. Treatment was delivered when the patient maintains this level of breath-hold. Treatment was performed with a 4 MV and 10 MV photon beams from a linear accelerator Varian 2100CS, equipped with a 120 leaves collimator. 60 Gy or 48 Gy were delivered, in four sessions, to the 80% isodose. The planning target volume (PTV) was defined by adding a 5mm margin to the internal target volume (ITV), the ITV corresponding to the gross tumour volume (GTV) plus a 3mm margin. CTV is considered equal to GTV. The non-understanding of the gating technique, the great number of beams and the limited breath-hold times led to the failure of some treatments. It can be explained by some patients insufficient respiratory abilities and the low dose rate of one of the beams used for treatment, thus forcing some radiation fields to be delivered in two or three times. Implementing such a technique can be limited by the patients' physical abilities and the materials used. Some solutions were found: a training phase more intense with a coaching of the breath-hold technique more precise, or the use of an abdominal compression device.

[Primitive metastasizing bronchial carcinoid with long survival]

BACKGROUND

Metastatic bronchial carcinoid tumours are rare but some patients have a prolonged survival. A new functional imagery now makes it possible to supplement the assessment of the extent of disease.

OBSERVATION

A 57 year old patient was referred for dyspnoea on exertion revealing an upper left lobar tumour, with carcinoid syndrome. The assessment enabled to find out a bronchial carcinoid tumour with liver and bone metastases, highlighted by positron-emission tomography and pentetreotide SPECT. A chemotherapy proved to be ineffective and upper left lobectomy was carried out because of the risk of pulmonary atelectasis. The patient was treated by somatostatin analogues then underwent liver transcatheter arterial chemo-embolization. The patient was alive 44 months after diagnosis (56 months after first computed tomography).

CONCLUSION

Metastatic bronchial carcinoid tumours are rare. They keep a metastatic potential, the histological type remaining the major prognosis factor. Carcinoid syndrome is suggestive. The assessment of extra-thoracic disease extent benefits by contribution of new functional imagery techniques such as the pentetreotide SPECT and positron-emission tomography. The management is essentially symptomatic since there is no effective chemotherapy. However survival can be prolonged, even in multimetastatic patients.

Prevalence of obesity, lipid and glucose abnormalities in outpatients prescribed clozapine

Individuals with schizophrenia have standardised mortality rates which are double that of the general population. In addition to suicide, high rates of cardiovascular and respiratory disease contribute to this raised mortality rate. Although clozapine has been reported to improve psychotic symptoms and decrease suicide rates, attention has recently focussed on its potential to increase cardiovascular risk factors including obesity, dyslipidemia and diabetes mellitus. This study aimed to ascertain the prevalence of these risk factors in a cohort of Irish outpatients treated with clozapine.

Prevalence of diabetic retinopathy in patients with diabetes mellitus diagnosed after the age of 70 years

AIMS/BACKGROUND

A hospital based prevalence study was undertaken to estimate the prevalence of diabetic retinopathy (DR) in patients diagnosed as having diabetes mellitus after the age of 70 years. The prevalence of visually threatening retinopathy at the time of diagnosis of diabetes was also determined. The association between prevalence of DR and duration of diabetes mellitus, mode of treatment, HbA1c levels, presence of hypertension, and sex of patient was examined and a comparison was drawn between this study and earlier prevalence studies of DR in older type II diabetics.

METHODS

Using data on the Irish Diabetic Retinopathy Register located in the Mater Misericordiae Hospital, Dublin, all patients who were diagnosed as having type II diabetes mellitus after the age of 70 years were invited to attend for ophthalmic review. Medical records were examined to determine the duration of diabetes mellitus, mode of treatment, recent HbA1c levels, and the presence of systemic hypertension.

RESULTS

Of the 150 patients examined, 21 (14%) had some form of DR and 10 of these patients (6.6%) had visually threatening retinopathy or previously treated visually threatening retinopathy. Five patients (3.3%) presented with visually threatening retinopathy at the time of diagnosis of diabetes. Those patients with DR had a significantly higher median duration of diabetes (5.0 years) compared with those patients without DR (3.5 years). A significantly higher proportion of patients with DR required treatment with insulin and a correspondingly lower proportion of patients without DR were controlled on diet alone. There was no significant association between prevalence of DR and HbA1c levels, systemic hypertension, or sex of patient. There was a lower overall prevalence of DR in comparison with earlier studies.

CONCLUSIONS

The prevalence of DR in these elderly type II diabetics is lower than than previously reported in patients with type II disease but a small percentage of patients had visually threatening retinopathy at presentation. Longer duration of diabetes and insulin use were associated with a significantly increased prevalence of DR. All elderly type II diabetic patients require thorough ophthalmic examination near to the time of first presentation and thereafter at regular intervals.