Genetic interaction in the association between oxidative stress and diabetes in the Spanish population

Oxidative stress (OS) is a relevant intermediate mechanism involved in Type 2 Diabetes Mellitus (T2D) development. To date, the interaction between OS parameters and variations in genes related to T2D has not been analyzed.

AIMS

To study the genetic interaction of genes potentially related to OS levels (redox homeostasis, renin-angiotensin-aldosterone system, endoplasmic stress response, dyslipidemia, obesity and metal transport) and OS and T2D risk in a general population from Spain (the Hortega Study) in relation to the risk of suffering from T2D.

MATERIALS AND METHODS

One thousand five hundred and two adults from the University Hospital Rio Hortega area were studied and 900 single nucleotide polymorphisms (SNPs) from 272 candidate genes were analyzed.

RESULTS

There were no differences in OS levels between cases and controls. Some polymorphisms were associated with T2D and with OS levels. Significant interactions were observed between OS levels and two polymorphisms in relation to T2D presence: rs196904 (ERN1 gene) and rs2410718 (COX7C gene); and between OS levels and haplotypes of the genes: SP2, HFF1A, ILI8R1, EIF2AK2, TXNRD2, PPARA, NDUFS2 and ERN1.

CONCLUSIONS

Our results indicate that genetic variations of the studied genes are associated with OS levels and that their interaction with OS parameters may contribute to the risk of developing T2D in the Spanish general population. These data support the importance of analyzing the influence of OS levels and their interaction with genetic variations in order to establish their real impact in T2D risk. Further studies are required to identify the real relevance of interactions between genetic variations and OS levels and the mechanisms involved in them.

Metabolomic patterns, redox-related genes and metals, and bone fragility endpoints in the Hortega Study

BACKGROUND

The potential joint influence of metabolites on bone fragility has been rarely evaluated. We assessed the association of plasma metabolic patterns with bone fragility endpoints (primarily, incident osteoporosis-related bone fractures, and, secondarily, bone mineral density BMD) in the Hortega Study participants. Redox balance plays a key role in bone metabolism. We also assessed differential associations in participant subgroups by redox-related metal exposure levels and candidate genetic variants.

MATERIAL AND METHODS

In 467 participants older than 50 years from the Hortega Study, a representative sample from a region in Spain, we estimated metabolic principal components (mPC) for 54 plasma metabolites from NMR-spectrometry. Metals biomarkers were measured in plasma by AAS and in urine by HPLC-ICPMS. Redox-related SNPs (N = 341) were measured by oligo-ligation assay.

RESULTS

The prospective association with incident bone fractures was inverse for mPC1 (non-essential and essential amino acids, including branched-chain, and bacterial co-metabolites, including isobutyrate, trimethylamines and phenylpropionate, versus fatty acids and VLDL) and mPC4 (HDL), but positive for mPC2 (essential amino acids, including aromatic, and bacterial co-metabolites, including isopropanol and methanol). Findings from BMD models were consistent. Participants with decreased selenium and increased antimony, arsenic and, suggestively, cadmium exposures showed higher mPC2-associated bone fractures risk. Genetic variants annotated to 19 genes, with the strongest evidence for NCF4, NOX4 and XDH, showed differential metabolic-related bone fractures risk.

CONCLUSIONS

Metabolic patterns reflecting amino acids, microbiota co-metabolism and lipid metabolism were associated with bone fragility endpoints. Carriers of redox-related variants may benefit from metabolic interventions to prevent the consequences of bone fragility depending on their antimony, arsenic, selenium, and, possibly, cadmium, exposure levels.

Arsenic, cadmium, and selenium exposures and bone mineral density-related endpoints: The HORTEGA study

BACKGROUND AND OBJECTIVES

Experimental data suggest that trace elements, such as arsenic (As), cadmium (Cd), and selenium (Se) can influence the bone remodeling process. We evaluated the cross-sectional association between As, Cd, and Se biomarkers with bone mineral density (BMD) measured at the calcaneus, in a representative sample of a general population from Spain. As secondary analyses we evaluated the associations of interest in subgroups defined by well-established BMD determinants, and also conducted prospective analysis of osteoporosis-related incident bone fractures restricted to participants older than 50 years-old.

METHODS

In N = 1365 Hortega Study participants >20 years-old, urine As and Cd were measured by inductively coupled-plasma mass spectrometry (ICPMS); plasma Se was measured by atomic absorption spectrometry (AAS) with graphite furnace; and BMD at the calcaneus was measured using the Peripheral Instaneuous X-ray Imaging system (PIXI). As levels were corrected for arsenobetaine (Asb) to account for inorganic As exposure.

RESULTS

The median of total urine As, Asb-corrected urine As, urine Cd, and plasma Se was 61.3, 6.53 and 0.39 μg/g creatinine, and 84.9 μg/L, respectively. In cross-sectional analysis, urine As and Cd were not associated with reduced BMD (T-score < -1 SD). We observed a non-linear dose-response of Se and reduced BMD, showing an inverse association below ~105 μg/L, which became increasingly positive above ~105 μg/L. The evaluated subgroups did not show differential associations. In prospective analysis, while we also observed a U-shape dose-response of Se with the incidence of osteoporosis-related bone fractures, the positive association above ~105 μg/L was markedly stronger, compared to the cross-sectional analysis.

CONCLUSIONS

Our results support that Se, but not As and Cd, was associated to BMD-related disease. The association of Se and BMD-related disease was non-linear, including a strong positive association with osteoporosis-related bone fractures risk at the higher Se exposure range. Considering the substantial burden of bone loss in elderly populations, additional large prospective studies are needed to confirm the relevance of our findings to bone loss prevention in the population depending on Se exposure levels.

Arsenic exposure, diabetes-related genes and diabetes prevalence in a general population from Spain

Inorganic arsenic exposure may be associated with diabetes, but the evidence at low-moderate levels is not sufficient. Polymorphisms in diabetes-related genes have been involved in diabetes risk. We evaluated the association of inorganic arsenic exposure on diabetes in the Hortega Study, a representative sample of a general population from Valladolid, Spain. Total urine arsenic was measured in 1451 adults. Urine arsenic speciation was available in 295 randomly selected participants. To account for the confounding introduced by non-toxic seafood arsenicals, we designed a multiple imputation model to predict the missing arsenobetaine levels. The prevalence of diabetes was 8.3%. The geometric mean of total arsenic was 66.0 μg/g. The adjusted odds ratios (95% confidence interval) for diabetes comparing the highest with the lowest tertile of total arsenic were 1.76 (1.01, 3.09) and 2.14 (1.47, 3.11) before and after arsenobetaine adjustment, respectively. Polymorphisms in several genes including IL8RA, TXN, NR3C2, COX5A and GCLC showed suggestive differential associations of urine total arsenic with diabetes. The findings support the role of arsenic on diabetes and the importance of controlling for seafood arsenicals in populations with high seafood intake. Suggestive arsenic-gene interactions require confirmation in larger studies.

Urine cadmium levels and albuminuria in a general population from Spain: A gene-environment interaction analysis

BACKGROUND

The interaction of cadmium with genes involved in oxidative stress, cadmium metabolism and transport pathways on albuminuria can provide biological insight on the relationship between cadmium and albuminuria at low exposure levels.

OBJECTIVES

We tested the hypothesis that specific genotypes in candidate genes may confer increased susceptibility to cadmium exposure.

METHODS

Cadmium exposure was estimated by inductively coupled plasma mass spectrometry (ICPMS) in urine from 1397 men and women aged 18-85years participating in the Hortega Study, a representative sample of a general population from Spain. Urine albumin was measured by automated nephelometric immunochemistry. Abnormal albuminuria was defined as urine albumin greater than or equal to 30mg/g.

RESULTS

The weighted prevalence of abnormal albuminuria was 6.3%. The median level of urine cadmium was 0.39 (IQR, 0.23-0.65) μg/g creatinine. Multivariable-adjusted geometric mean ratios of albuminuria comparing the two highest to the lowest tertile of urine cadmium were 1.62 (95% CI, 1.43-1.84) and 2.94 (95% CI, 2.58-3.35), respectively. The corresponding odds ratios of abnormal albuminuria were 1.58 (0.83, 3.02) and 4.54 (2.58, 8.00). The association between urine cadmium and albuminuria was observed across all participant subgroups evaluated including participants without hypertension, diabetes or chronic kidney disease. We observed Bonferroni-corrected statistically significant interactions between urine cadmium levels and polymorphisms in gene SLC30A7 and RAC1.

CONCLUSIONS

Increasing urine cadmium concentrations were cross-sectionally associated with increased albuminuria in a representative sample of a general population from Spain. Genetic variation in oxidative stress and cadmium metabolism and transport genes may confer differential susceptibility to potential cadmium effects.

In-hospital mortality due to infectious disease in an Internal Medicine Department. Epidemiology and risk factors

OBJECTIVE

Hospital mortality is a leading indicator of quality of healthcare and a valuable tool for planning and management. Infectious diseases represent a substantial part of the activity of internal medicine.Our aim was to describe the characteristics of in-hospital mortality due to infectious diseases and associated risk factors in our environment.

MATERIALS AND METHODS

A retrospective case-control study was designed. We reviewed deaths during 2012 from an Internal Medicine Department. 187 cases (infectious disease related mortality) and 224 controls were found. Clinical and demographic information was obtained from medical records. Comorbidity was evaluated with Charlson index (CI). Data were analyzed using SPSS 15.0 (p-value < 0.05).

RESULTS

During 2012, of the 3193 discharge, 187 were exitus due to infectious disease (5.8%). Mean age was 85.7 ± 7.6, higher in women (88 ± 7 vs 83 ± 7.4, p < 0.001), and 55% were aged over 85 years. The CI mean was 4.2 ± 3, higher in younger than 85 years (5.3 ± 3.4 vs 3.6 ± 2.6, p < 0.001). Most frequent causes of death were respiratory sepsis (29%), severe pneumonia (23.5%) and urinary sepsis (16.6%) and risk factors were living in Nursing Home (55.6% vs 34%, p < 0.001), being dependent (73.8% vs. 44.6%, p < 0.001), dementia (59.4% vs 27.2%, p < 0.001) and cerebrovascular disease (25.7% vs 17.4%, p = 0.041).

CONCLUSIONS

Dementia, cerebrovascular disease, living in Nursing Home and being dependent were risk factors for infectious disease in-hospital mortality in our study, but not comorbidity, age or length of stay. Our series, although limited by retrospective design, is the first qualitative study of in-hospital mortality due to infectious disease in an Internal Medicine Service in our environment. Most frequent cause of death in our setting was respiratory etiology.

Epidemiology, risk factors and comorbidity for urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing enterobacteria

AIM

Urinary tract infection (UTI) caused by resistant bacteria is becoming more prevalent. We investigate characteristics and associated risk factors for UTIs resulting from extended-spectrum beta-lactamase (ESBL)-producing enterobacteria.

METHODS

Retrospective study of urinary tract isolates of ESBL-producing enterobacteria in adults (2009 and 2010). We included 400 patients and 103 controls (UTI caused by non-ESBL Escherichia coli). Clinical and demographic information was obtained from medical records. Comorbidity was evaluated using Charlson Index (CI). Strains were identified using VITEK 2 system.

RESULTS

A total of 400 isolates were obtained (93%E. coli and 7%Klebsiella spp). In 2009, 6% of cultures were ESBL-producing E. coli and 7% in 2010. 37% of patients were men and 81% were aged ≥60years. CI was 2.3±1.8 (high comorbidity: 42.8%). 41.5% of strains were susceptible to amoxicillin-clavulanate, 85.8% to fosfomycin and 15.5% to ciprofloxacin. The total number of ESBL E. coli positive urine cultures during hospital admission was 97 and, compared with 103 controls, risk factors for UTI caused by ESBL- E. coli strains in hospitalised patients were nursing home residence (p<0.001), diabetes (p=0.032), recurrent UTI (p=0.032) and high comorbidity (p=0.002). In addition, these infections were associated with more symptoms (p<0.001) and longer admission (p=0.004).

CONCLUSIONS

Urinary tract infection caused by ESBL are a serious problem and identifying risk factors facilitates early detection and improved prognosis. Male sex, hospitalisation, institutionalisation, diabetes, recurrent UTI and comorbidity were risk factors and were associated with more symptoms and longer hospital stay.

Depression and health related quality of life among HIV-infected people

BACKGROUND AND OBJECTIVES

Little is known about the impact of comorbid psychiatric symptoms in health related quality of life (HRQL) in patients with HIV infection. The aim of this investigation was to describe depressive symptoms and the impact in HRQL in HIV infected people.

MATERIALS AND METHODS

A cross-sectional study over 150 HIV-outpatients in a tertiary hospital was designed. Depression data were obtained using the Beck Depression Inventory, Second Edition (BDI-II) inventory. HRQL data were collected by disease-specific questionnaire MOS-HIV. Researchers' team designed a specific template to get rest of the data.

RESULTS

Almost three-quarters of the population were men. After adjusting for gender and age, HIV-related symptoms and presence of depression were found to be negatively associated with all the Medical Outcomes Study HIV Health Survey (MOS-HIV) general domains and in the Physical Health Summary score and Mental Health Summary score.

CONCLUSIONS

Optimization of HRQL is particularly important now that HIV is a chronic disease with the prospect of long-term survival. Quality of life and depression should be monitored in follow-up of HIV infected patients. Comorbid psychiatric conditions may serve as markers for impaired functioning and well-being in persons with HIV.

[Family physician's role in the HIV infection management]

The human immunodeficiency virus (HIV) infection is a disease with great sociosanitary impact. Since 1981, when the first cases of AIDS were described, more than 60 million people have become infected. During these 25 years there have been a lot of advances in the infection management and we know that prevention and early diagnosis are crucial. Family Physician s role is essential since this is a privileged point of global attention, counseling and support for these patients. The main objective is to reduce the new HIV infections incidence. In addition, other objectives are: primary prevention and health promotion, early diagnosis, recruitment infected patients, monitoring and end-of-life caring. It is important to know that all of us are susceptible to contract the virus and, although the HIV testing is voluntary, there are screening recommendations from the CDC: persons with signs or symptoms that suggest infection, pregnant women, persons at high risk for infection and all patients aged 13-64 years, as a part of routine clinical care. The communication of the result is a key point in the therapeutic relation. If it is negative we must make intervention on risk attitudes. If it is positive we must inform and support the patient, to convince him about the need to be followed up by an specialized level. The AIDS terminal patient is a very immunodeficient one and needs palliative cares like other terminal disease. Another challenge is prevention and control of HIV infection among the immigrant community. In conclusion, Family Physicians must investigate risk practices, inform, prevent new cases and, in the infected people, monitor the evolution, supporting and comforting.