Risk factors in metabolic syndrome predict the progression of diabetic nephropathy in patients with type 2 diabetes

Effect of a home-based physical activity program on metabolic syndrome in Ghanaian adults with type 2 diabetes: Protocol for a feasibility randomized controlled trial

AIM

To describe the protocol of a feasibility trial designed to test the preliminary effect of a 12-week culturally appropriate physical activity programme on metabolic syndrome markers and quality of life in Ghanaian adults with type 2 diabetes (T2DM).

DESIGN

Feasibility randomised controlled trial.

METHODS

Through random allocation, 90 adults with T2DM will be allocated to either the control group (CG) (n = 45) or the intervention group (IG) (n = 45). The IG will receive the physical activity programme in addition to their usual diabetes care; those in the CG will receive their usual diabetes care. Measurements will be performed at baseline and 12-week follow-up. The primary outcome is a change in metabolic syndrome markers in the IG compared to the CG. Secondary outcomes are: (a) a change in quality of life in the IG compared to the CG, (b) the feasibility of implementation.

RESULTS

Findings will inform the design of a future large-scale trial.

PATIENT OR PUBLIC CONTRIBUTION

Patients with T2DM and their healthcare professionals contributed to this study protocol by participating in semi-structured interviews towards the design of the physical activity programme.

CLINICAL TRIAL REGISTRATION NUMBER

The trial is registered in the Australian and New Zealand Clinical Trial Registry (registration number: ACTRN12622000323729p).

Association of matrix metalloproteinase-2 gene variants with diabetic nephropathy risk

BACKGROUND

Diabetic nephropathy is a highly destructive microvascular complication of diabetes. Genetic predisposition is involved in the pathogenesis of diabetic nephropathy, with multiple allelic polymorphisms associated with the development and progression of the disease, thereby increasing the overall risk. To date, no study is available that shows the association of matrix metalloproteinase-2 (MMP-2) gene polymorphisms with diabetic nephropathy risk. Thus, we investigated the potential genetic influence of MMP-2 promoter variants in the development of diabetic nephropathy in type 2 diabetic patients.

METHODS

In total, 726 type 2 diabetic patients and 310 healthy controls were included in the study and genotyped for MMP-2, -1306C/T, -790T/G, -1575G/T and -735C/T by real-time PCR. The analysis of the outcomes was performed assuming three genetic models. The threshold for statistical significance was set at 0.05.

RESULTS

The results showed that the minor allele frequency of the -790T/G variant was significantly higher in patients with and without nephropathy compared to controls. Furthermore, the distribution analysis revealed a significant association of the -790T/G variant, in all genetic models, with increased risk of diabetic nephropathy that persisted after adjusting for key covariates. No significant associations between MMP-2, -1306C/T, -1575G/T, -735C/T and the risk of diabetic nephropathy were detected. Haplotype analysis identified two risk haplotypes GCGC and GTAC associated with diabetic nephropathy.

CONCLUSIONS

The present study is the first to demonstrate the allelic and genotypic association of the MMP-2-790T/G variant and two haplotypes with an increased risk of diabetic nephropathy in a Tunisian population with type 2 diabetes.

Obesity Metabolic Phenotypes and Unplanned Readmission Risk in Diabetic Kidney Disease: An Observational Study from the Nationwide Readmission Database

BACKGROUND AND AIM

Obesity is a potentially modifiable factor for reducing readmissions, with heterogeneity that varies according to the metabolic status. Our objective was to examine the independent or mutual relationship between obesity and metabolic abnormalities and diabetic kidney disease (DKD)-related hospitalizations.

METHODS

493,570 subjects with DKD were enrolled in the 2018 Nationwide Readmission Database (NRD, United States). The at-risk population was reclassified into refined obesity subtypes based on the body mass index (BMI) classification of metabolic abnormalities (hypertension and/or dyslipidemia) to investigate the 180 d readmission risk and hospitalization costs related to DKD.

RESULTS

The overall readmission rate was 34.1%. Patients with metabolic abnormalities, regardless of obesity, had a significantly higher risk of readmission compared to non-obese counterparts (adjusted HR, 1.11 [95% CI, 1.07-1.14]; 1.12 [95% CI, 1.08-1.15]). Hypertension appeared to be the only metabolic factor associated with readmission among individuals with DKD. Obesity without metabolic abnormalities was independently associated with readmission (adjusted HR,1.08 [1.01,1.14]), especially among males and those >65 years (adjusted HR,1.10 [1.01-1.21]; 1.20 [1.10-1.31]). Women or those ≤65 years with metabolic abnormalities (all p <0.050) had elevated readmission rates, regardless of obesity; however, no such trend was observed in obese subjects without metabolic abnormalities (adjusted HR, 1.06 [0.98,1.16]). Additionally, obesity and metabolic abnormalities were associated with elevated hospitalization costs (all p <0.0001).

CONCLUSIONS

Increased BMI and hypertension are positively associated with readmissions and related costs among patients with DKD, which should be considered in future studies.

Effect of Physical Activity on Metabolic Syndrome Markers in Adults with Type 2 Diabetes: A Systematic Review and Meta-Analysis

People with Type 2 diabetes mellitus (T2DM) are reported to have a high prevalence of metabolic syndrome (MetS), which increases their risk of cardiovascular events. Our aim was to determine the effect of physical activity (PA) on metabolic syndrome markers in people with T2DM. The study design was a systematic review and meta-analysis of randomised controlled trials evaluating the effect of PA on MetS in adults with T2DM. Relevant databases including SPORTdiscus, Cochrane Central Register of Controlled Trials, CINAHL, MEDLINE, PsycINFO, EMBASE, SocINDEX were searched up to August 2022. Primary endpoints were changes in MetS markers (blood pressure, triglyceride, high-density lipoprotein, fasting blood sugar, and waist circumference) after an exercise intervention. Using a random effect model with 95% confidence interval (CI), the mean difference between intervention groups and control groups were calculated. Twenty-six articles were included in the review. Overall, aerobic exercise had a significant effect on waist circumference (Mean Difference: -0.34 cm, 95% CI: -0.84, -0.05; effect size: 2.29, I² = 10.78%). The effect sizes on blood pressure, triglyceride, high-density lipoprotein, fasting blood sugar were not statistically significant. No significant differences were found between exercise and control group following resistance training. Our findings suggest that aerobic exercise can improve waist circumference in people with T2DM and MetS. However, both aerobic and resistance exercise produced no significant difference in the remaining MetS markers. Larger and higher-quality studies are required to determine the full effects of PA on MetS markers in this population.

The Effect of Metabolic Syndrome and Its Individual Components on Renal Function: A Meta-Analysis

BACKGROUND

Observational studies have reported inconsistent findings in the relationship between metabolic syndrome (MetS), its components, and loss of renal function, mainly including eGFR decline, new-onset CKD, and ESRD. This meta-analysis was performed to investigate their potential associations.

METHODS

PubMed and EMBASE were systematically searched from their inception to 21 July 2022. Observational cohort studies in English assessing the risk of renal dysfunction in individuals with MetS were identified. Risk estimates and their 95% confidence intervals (CIs) were extracted and pooled using the random-effects approach.

RESULTS

A total of 32 studies with 413,621 participants were included in the meta-analysis. MetS contributed to higher risks of renal dysfunction (RR = 1.50, 95% CI = 1.39-1.61) and, specifically, rapid decline in eGFR (RR 1.31, 95% CI 1.13-1.51), new-onset CKD (RR 1.47, 95% CI 1.37-1.58), as well as ESRD (RR 1.55, 95% CI 1.08-2.22). Moreover, all individual components of MetS were significantly associated with renal dysfunction, while elevated BP conveyed the highest risk (RR = 1.37, 95% CI = 1.29-1.46), impaired fasting glucose with the lowest and diabetic-dependent risk (RR = 1.20, 95% CI = 1.09-1.33).

CONCLUSIONS

Individuals with MetS and its components are at higher risk of renal dysfunction.

Common gene signatures and molecular mechanisms of diabetic nephropathy and metabolic syndrome

Background

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. Multiple metabolic toxicities, redox stress, and endothelial dysfunction contribute to the development of diabetic glomerulosclerosis and DN. Metabolic syndrome (MetS) is a pathological state in which the body's ability to process carbohydrates, fats, and proteins is compromised because of metabolic disorders, resulting in redox stress and renal remodeling. However, a causal relationship between MetS and DN has not been proven. This study aimed to provide valuable information for the clinical diagnosis and treatment of MetS with DN.

Methods

Here, transcriptome data of DN and MetS patients were obtained from the Gene Expression Omnibus database, and seven potential biomarkers were screened using bioinformatics analysis. In addition, the relationship between these marker genes and metabolism and immune infiltration was explored. Among the identified marker genes, the relationship between PLEKHA1 and the cellular process, oxidative phosphorylation (OXPHOS), in DN was further investigated through single-cell analysis.

Results

We found that PLEKHA1 may represent an important biomarker that perhaps initiates DN by activating B cells, proximal tubular cells, distal tubular cells, macrophages, and endothelial cells, thereby inducing OXPHOS in renal monocytes.

Conclusion

Overall, our findings can aid in further investigation of the effects of drug treatment on single cells of patients with diabetes to validate PLEKHA1 as a therapeutic target and to inform the development of targeted therapies.

Development and validation of a risk prediction model for chronic kidney disease among individuals with type 2 diabetes

Many studies had established the chronic kidney disease (CKD) prediction models, but most of them were conducted on the general population and not on patients with type 2 diabetes, especially in Asian populations. This study aimed to develop a risk prediction model for CKD in patients with type 2 diabetes from the Diabetes Care Management Program (DCMP) in Taiwan. This research was a retrospective cohort study. We used the DCMP database to set up a cohort of 4,601 patients with type 2 diabetes without CKD aged 40–92 years enrolled in the DCMP program of a Taichung medical center in 2002–2016. All patients were followed up until incidences of CKD, death, and loss to follow-up or 2016. The dataset for participants of national DCMP in 2002–2004 was used as external validation. The incident CKD cases were defined as having one of the following three conditions: ACR data greater than or equal to 300 (mg/g); both eGFR data less than 60 (ml/min/1.73 m²) and ACR data greater than or equal to 30 (mg/g); and eGFR data less than 45 (ml/min/1.73 m²). The study subjects were randomly allocated to derivation and validation sets at a 2:1 ratio. Cox proportional hazards regression model was used to identify the risk factors of CKD in the derivation set. Time-varying area under receiver operating characteristics curve (AUC) was used to evaluate the performance of the risk model. After an average of 3.8 years of follow-up period, 3,067 study subjects were included in the derivation set, and 786 (25.63%) were newly diagnosed CKD cases. A total of 1,534 participants were designated to the validation set, and 378 (24.64%) were newly diagnosed CKD cases. The final CKD risk factors consisted of age, duration of diabetes, insulin use, estimated glomerular filtration rate, albumin-to-creatinine ratio, high-density lipoprotein cholesterol, triglyceride, diabetes retinopathy, variation in HbA1c, variation in FPG, and hypertension drug use. The AUC values of 1-, 3-, and 5-year CKD risks were 0.74, 0.76, and 0.77 in the validation set, respectively, and were 0.76, 0.77, and 0.76 in the sample for external validation, respectively. The value of Harrell’s c-statistics was 0.76 (0.74, 0.78). The proposed model is the first CKD risk prediction model for type 2 diabetes patients in Taiwan. The 1-, 3-, and 5-year CKD risk prediction models showed good prediction accuracy. The model can be used as a guide for clinicians to develop medical plans for future CKD preventive intervention in Chinese patients with type 2 diabetes.

Prognostic value of metabolic syndrome in renal structural changes in type 2 diabetes

PURPOSE

To investigate the prognostic value of metabolic syndrome (MetS) and its relationship with renal structure changes in patients with type 2 diabetes and associated diabetic nephropathy (DN).

METHODS

411 Chinese patients with type 2 diabetes and biopsy-confirmed DN were enrolled in this retrospective study. MetS was defined according to the modified criteria of the 2005 International Diabetes Federation. Baseline demographics and clinical information at the time of renal biopsy were extracted from the hospital's electronic medical records system. Renal pathological findings were assessed according to Renal Pathology Society system. Univariate and multivariate logistic regression analyses were performed to define the pathological covariates associated with MetS. A competing risk model, with death as the competing risk, was used to estimate the sub-distribution hazard ratio (SHR) of MetS for end-stage kidney disease (ESKD).

RESULTS

224 (55%) patients had MetS. Patients with MetS had poor renal function and more severe interstitial fibrosis tubular atrophy scores (IFTA) than those without MetS. Multivariate logistic regression analysis revealed that IFTA was significantly associated with MetS (odds ratio per score increase 1.45, 95% confidence interval [CI] 1.02-2.05). Of the patients with DN at risk, 40% of patients progressed to ESKD. After adjusting for renal function and pathological parameters, the presence of MetS was an independent predictor for progression to ESKD (SHR 1.93, 95% CI 1.34-2.79). The SHRs for progression to ESKD also increased as the number of MetS components increased. Additionally, adding the IFTA scores improved the prognostic power of a model that only contained MetS and clinical covariates for predicting future ESKD.

CONCLUSION

MetS is an independent prognostic predictor of ESKD in patients with T2D and DN, while adding the IFTA scores increased the prognostic value of MetS for renal outcome.

Potential Molecular Mechanism of Yishen Capsule in the Treatment of Diabetic Nephropathy Based on Network Pharmacology and Molecular Docking

PURPOSE

Using network pharmacology and molecular docking to explore the mechanism of Yishen Capsule in the treatment of diabetic nephropathy.

MATERIALS AND METHODS

Active components of Yishen Capsule were obtained using database such as TCMSP and TCMID. UniProt protein database was used to screen and standardize the human-derived targets of the active chemical components. Diabetic nephropathy (DN) targets were obtained from databases such as GeneCards, OMIM, TTD, DisGeNET and DrugBank. A network of "Yishen Capsule Components-diabetic nephropathy Targets-Pathways" was constructed by analyzing data above to screening out core targets for molecular docking verification. DN is induced by streptozocin in rats after left nephrectomy. Renal tubular epithelial cells (RTECs) was isolated  and cultured under high glucose conditions. Based on these experimental models, key pathway target genes screened by network pharmacology were verified both in vitro and in vivo.

RESULTS

The main active components of Yishen Capsule in the treatment of DN include quercetin, kaempferol, gallic acid, astragaloside IV, etc. Some key targets (such as AR, AKT1, TP53, ESR1, JUN) and important signal pathways (such as AGE-RAGE, HIF-1 and JAK-STAT signal pathway) were included in the treatment of DN with Yishen Capsule. Molecular docking assay showed that most of the targets have good binding activity with the components of Yishen Capsule. Based on the results of network pharmacology, key target proteins in HIF-1α and JAK2/STAT3 signaling pathways were selected for experimental verification. Results presented that HIF-1α, JAK2, STAT3, TGF-β and MCP-1 were increased under high glucose environment. With the treatment of Yishen Capsule, the expression of HIF-1α further increased, while the expression of JAK2, STAT3, MCP-1 and TGF-β was decreased.

CONCLUSION

This study revealed the mechanism of Yishen Capsule in the treatment of DN, which possesses the characteristics of multi-component, multi-target, and multi-pathway. Further experiments confirmed that Yishen Capsule interfered with HIF-1α and JAK/STAT signaling pathways to reduce inflammation and fibrosis damage in the kidney tissue of rats with diabetic nephropathy.

Epidemiological characteristics of diabetic kidney disease in Taiwan

Diabetic kidney disease (DKD) is a critical microvascular complication of diabetes. With the continuous increase in the prevalence of diabetes since 2000, the prevalence of DKD has also been increasing in past years. The prevalence of DKD among individuals with type 2 diabetes in Taiwan increased from 13.32% in 2000 to 17.92% in 2014. The cumulative incidence of DKD among individuals with type 1 diabetes in Taiwan was higher than 30% during 1999-2012. DKD is the leading cause of end-stage renal disease (ESRD), with a prevalence of approximately 45% in a population on chronic dialysis in Taiwan. Among individuals with type 2 diabetes, the prevalence of ESRD in the receipt of dialysis also increased from 1.32% in 2005 to 1.47% in 2014. Risk factors for DKD development are age, race, family history, hyperglycemia, hypertension, dyslipidemia, dietary patterns, and lifestyles. Prognostic factors that aggravate DKD progression include age, family history, sex, glycemic control, blood pressure (BP), microvascular complications, and atherosclerosis. This review summarizes updated information on the onset and progression of DKD, particularly in the Taiwanese population. Translating these epidemiological features is essential to optimizing the kidney care and improving the prognosis of DKD in Asian populations.

The association between fat-to-muscle ratio and metabolic disorders in type 2 diabetes

BACKGROUND

Altered body composition is known to be related to abnormal metabolism. The aim of this study was to determine the association between the fat-to-muscle ratio (FMR) and metabolic disorders in type 2 diabetes (T2DM) population.

METHOD

In total, 361 T2DM participants aged ≥ 18 years were included in our research. A bioelectrical impedance analyzer was applied to measure fat mass and muscle mass. FMR was calculated as body fat mass (kg) divided by muscle mass (kg). The performance of FMR to assess metabolic disorders in T2DM was conducted using ROC curves. The independent association between FMR and metabolic syndrome (MS) was tested by logistic regression analysis.

RESULTS

The FMR was significantly higher in patients with MS than in those without MS (p < 0.001). The optimal FMR cutoff point for identifying MS was higher in females than in males (0.465 vs. 0.296, respectively). In addition, the areas under the ROC curve (AUCs) for the evaluation of MS by FMR, fat mass, muscle mass, BMI and waist circumference were further compared, indicating that the AUC of FMR (0.843) was the largest among the five variables in females, but the AUC of waist circumference (0.837) was still the largest among other variables in males. Based on the derived FMR cutoff point, patients with a high FMR exhibited more cardiometabolic risk indicators (all p < 0.05). Using a low FMR as a reference, the relative risk of a high FMR for MS was 2.861 (95% CI 1.111-7.368, p = 0.029) in males and 9.518 (95% CI 2.615-34.638, p = 0.001) in females following adjustment for confounding factors.

CONCLUSIONS

The fat-to-muscle ratio is independently and positively associated with metabolic disorders in T2DM. FMR may serve as an optimal method for screening T2DM patients coupled with a high risk of abnormal metabolism, especially in females, providing a new perspective for the prevention and treatment of cardiovascular complications in Chinese type 2 diabetes.

The Efficacy of Hydroxychloroquine Combined with Huangqi Tablets in the Treatment of Diabetic Nephropathy

Objective

This study aimed to analyze the effect of hydroxychloroquine combined with Huangqi tablets in the treatment of diabetic nephropathy (DN).

Methods

Eighty patients with DN were enrolled and divided into two groups by a random number table. 27 patients received routine treatment + hydroxychloroquine (group A), while 27 patients received routine treatment + hydroxychloroquine + Huangqi tablets (group B) and 26 patients received routine treatment (group C).

Results

FPG, 2h PG, and HbA1c levels as well as TC and TG levels were lower in group B than in groups A and C at the end of 3 months of treatment and were lower in group A than in group C (P < 0.05). SCR, BUN, and 24-hour urine protein were reduced in group B after therapy, whereas eGFR was increased and the difference between groups A and C was significant (P=0.05). After treatment, VEGF, IGF-1, and TGF-1 levels were lower in group B than in groups A and C and in group A than in group C (P=0.05). Total symptom scores at 2, 4, and 6 months after treatment was lower in group B than in groups A and C, and they were lower in group A than in group C at all time points (P < 0.05). The total effective rates of treatment in groups A, B, and C were 66.67%, 88.89%, and 38.46% (P < 0.05). The incidence of adverse reactions in groups A, B, and C was 37.04%, 25.93%, and 11.54% (P > 0.05).

Conclusion

Hydroxychloroquine combined with Huangqi tablets in the treatment of DN showed the best efficacy, with better control of blood glucose and lipids, which can more effectively delay the progression of renal lesions and effectively inhibit the expression of VEGF, IGF, and TGF-β1 in tethered cells with high safety.

Using Latent Class Analysis to Identify Different Risk Patterns for Patients With Masked Hypertension

Background: There is controversy whether masked hypertension (MHT) requires additional intervention. The aim of this study is to evaluate whether MHT accompanied with high-risk metabolic syndrome (MetS), as the subphenotype, will have a different prognosis from low-risk MetS.

Methods: We applied latent class analysis to identify subphenotypes of MHT, using the clinical and biological information collected from High-risk Cardiovascular Factor Screening and Chronic Disease Management Programme. We modeled the data, examined the relationship between subphenotypes and clinical outcomes, and further explored the impact of antihypertensive medication.

Results: We included a total of 140 patients with MHT for analysis. The latent class model showed that the two-class (high/low-risk MetS) model was most suitable for MHT classification. The high-risk MetS subphenotype was characterized by larger waist circumference, lower HDL-C, higher fasting blood glucose and triglycerides, and prevalence of diabetes. After four years of follow-up, participants in subphenotype 1 had a higher non-major adverse cardiovascular event (MACE) survival probability than those in subphenotype 2 (P = 0.016). There was no interaction between different subphenotypes and the use of antihypertensive medications affecting the occurrence of MACE.

Conclusions: We have identified two subphenotypes in MHT that have different metabolic characteristics and prognosis, which could give a clue to the importance of tracing the clinical correlation between MHT and metabolic risk factors. For patients with MHT and high-risk MetS, antihypertensive therapy may be insufficient.

Predictive Role of Child-To-Adult Blood Pressure Trajectories for Incident Metabolic Syndrome: 30-Year Hanzhong Adolescent Hypertension Study

OBJECTIVE

The relationship between child-to-adult blood pressure (BP) trajectories and metabolic syndrome (MetS) is unknown. We aimed to determine the predictive role of BP trajectories for incident MetS and its components.

METHODS

The prospective Hanzhong Adolescent Hypertension study began in 1987 and included 2692 participants free of MetS at baseline with at least 3 BP measurements available from 1987 to 2017.

RESULTS

The systolic BP (SBP) trajectory patterns were grouped as normal (class 1, 18.7%), high normal (class 2, 60.3%), prehypertensive (class 3, 13.1%), stage 1 hypertensive (class 4, 5.7%), and stage 2 hypertensive (class 5, 2.2%). Compared with those in the normal group, individuals in classes 2 to 5 had significantly higher risks of MetS (all Ps < .05), and those with hypertension had more than an 8-fold higher risk of MetS (both P < .05). The fully adjusted risk ratios (RRs) of central obesity increased significantly in a stepwise manner as the SBP trajectory group increased from class 1 to class 5 (P < .05). Compared with those with a normal SBP trajectory, participants in the prehypertensive group and stage 1 and stage 2 hypertensive groups had significantly higher RRs for high-risk triglycerides after full adjustment (RR = 1.89 [1.22-2.94]; RR = 3.61 [2.16-6.02]; and RR = 3.22 [1.52-6.84], respectively).

CONCLUSION

Our study suggests that BP trajectories are predictive of incident MetS outcomes. Early detection of hypertension or modest elevations in BP is crucial. The stage of hypertension based on SBP level showed a greater association with central obesity.

Metabolic syndrome in patients with type 2 diabetes and atherosclerotic cardiovascular disease: a post hoc analyses of the EMPA-REG OUTCOME trial

Background

Patients with type 2 diabetes (T2D) and metabolic syndrome (MetS) are at greater cardiovascular risk than those with T2D without MetS. In the current report we aim to study the characteristics, cardio-renal outcomes and the effect of empagliflozin in patients with MetS enrolled in the EMPA-REG OUTCOME trial.

Methods

A total of 7020 patients with T2D and atherosclerotic cardiovascular disease were treated with empagliflozin (10 mg or 25 mg) or placebo for a median of 3.1 years. The World Health Organization MetS criteria could be determined for 6985 (99.5%) patients. We assessed the association between baseline MetS and multiple cardio-renal endpoints using Cox regression models, and we studied the change in the individual component over time of the MetS using mixed effect models.

Results

MetS at baseline was present in 5740 (82%) patients; these were more often white and had more often albuminuria and heart failure, had lower eGFR and HDL-cholesterol, and higher blood pressure, body mass index, waist circumference, and triglycerides. In the placebo group, patients with MetS had a higher risk of all outcomes including cardiovascular death: HR = 1.73 (95% CI 1.01–2.98), heart failure hospitalization: HR = 2.64 (95% CI 1.22, 5.72), and new or worsening nephropathy: HR = 3.11 (95% CI 2.17–4.46). The beneficial effect of empagliflozin was consistent on all cardio-renal outcomes regardless of presence of MetS.

Conclusions

A large proportion of the EMPA-REG OUTCOME population fulfills the criteria for MetS. Those with MetS had increased risk of adverse cardio-renal outcomes. Compared with placebo, empagliflozin improved cardio-renal outcomes in patients with and without MetS.

Trial registration Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT 01131676