Shorter History of Hypertension as a Predictor of Hypertension Remission after 3-years of Bariatric Surgery: Data from the GATEWAY Trial

BACKGROUND

Previous evidence explored predictors of hypertension (HTN) remission after bariatric but data are limited to observational studies and lack of ambulatory blood pressure monitoring (ABPM). This study was aimed to evaluate the rate of HTN remission after bariatric surgery using ABPM and to define predictors of mid-term HTN remission.

METHODS

We included patients enrolled in the surgical arm of the GATEWAY randomized trial. HTN remission was defined as controlled blood pressure (< 130 × 80 mmHg) evaluated by 24-h ABPM while no need of anti-hypertensive medications after 36 months. A multivariable logistic regression model was used to assess the predictors of HTN remission after 36 months.

RESULTS

46 patients submitted Roux-en-Y gastric bypass (RYGB). HTN remission occurred in 39% (n = 14 out of 36 patients with complete data at 36 months). Patients with HTN remission had shorter HTN history than no remission group (5.9 ± 5.5 vs. 12.5 ± 8.1 years; p = 0.01). The baseline insulin levels were lower in patients who presented HTN remission, although not statistically significant (OR: 0.90; CI 95%: 0.80-0.99; p = 0.07). In the multivariate analysis, the HTN history (years) was the only independent predictor of HTN remission (OR: 0.85; 95% CI: 0.70-0.97; p = 0.04). Therefore, for each additional year of HTN history, the chance of HTN remission decreases by approximately 15% after RYGB.

CONCLUSION

After 3 years of RYGB, HTN remission defined by ABPM was common and independently associated with a shorter HTN history. These data underscore the need of early effective approach of obesity aiming greater impact in its comorbidities.

Three-Year Outcomes of Bariatric Surgery in Patients With Obesity and Hypertension : A Randomized Clinical Trial

BACKGROUND

Midterm effects of bariatric surgery on patients with obesity and hypertension remain uncertain.

OBJECTIVE

To determine the 3-year effects of Roux-en-Y gastric bypass (RYGB) on blood pressure (BP) compared with medical therapy (MT) alone.

DESIGN

Randomized clinical trial. (ClinicalTrials.gov: NCT01784848).

SETTING

Investigator-initiated study at Heart Hospital (HCor), São Paulo, Brazil.

PARTICIPANTS

Patients with hypertension receiving at least 2 medications at maximum doses or more than 2 medications at moderate doses and with a body mass index (BMI) between 30.0 and 39.9 kg/m² were randomly assigned (1:1 ratio).

INTERVENTION

RYGB plus MT or MT alone.

MEASUREMENTS

The primary outcome was at least a 30% reduction in total number of antihypertensive medications while maintaining BP less than 140/90 mm Hg. Key secondary outcomes were number of antihypertensive medications, hypertension remission, and BP control according to current guidelines (<130/80 mm Hg).

RESULTS

Among 100 patients (76% female; mean BMI, 36.9 kg/m² [SD, 2.7]), 88% from the RYGB group and 80% from the MT group completed follow-up. At 3 years, the primary outcome occurred in 73% of patients from the RYGB group compared with 11% of patients from the MT group (relative risk, 6.52 [95% CI, 2.50 to 17.03]; P < 0.001). Of the randomly assigned participants, 35% and 31% from the RYGB group and 2% and 0% from the MT group achieved BP less than 140/90 mm Hg and less than 130/80 mm Hg without medications, respectively. Median (interquartile range) number of medications in the RYGB and MT groups at 3 years was 1 (0 to 2) and 3 (2.8 to 4), respectively (P < 0.001). Total weight loss was 27.8% and -0.1% in the RYGB and MT groups, respectively. In the RYGB group, 13 patients developed hypovitaminosis B₁₂ and 2 patients required reoperation.

LIMITATION

Single-center, nonblinded trial.

CONCLUSION

RYGB is an effective strategy for midterm BP control and hypertension remission, with fewer medications required in patients with hypertension and obesity.

PRIMARY FUNDING SOURCE

Ethicon, represented in Brazil by Johnson & Johnson do Brasil.

Abstract P374: 24-h Blood Pressure Profile, Non-dipping Status And Incidence Of Resistant Hypertension In Patients Randomized To Bariatric Surgery Versus Medical Therapy: The Gateway Randomized Trial

Background: Bariatric surgery represents an effective strategy for office blood pressure (BP) reduction in obese hypertensive patients. However, no previous study evaluated the impact of bariatric surgery on 24-h BP profile, non-dipping status and incidence of resistant hypertension (RH).

Methods: This is a sub-analysis of a randomized clinical trial including hypertensive patients with grade 1 and 2 obesity, aged 18 to 65 years, using at least 2 drugs at optimal doses or >2 at moderate doses. Patients were randomly allocated to either Roux-en-Y Gastric Bypass (RYGB) with medical therapy (MT) or MT alone for 12 months. We analyzed the 24-h BP profile, non-dipping status (defined by <10% of systolic BP reduction during sleep as compared to the daytime period) and RH incidence.

Results: A total of 100 patients were included (76% female, age 43.8±9.2 years, BMI 36.9±2.7 Kg/m 2 ). The 24-h BP profile was similar at 12 months in both groups, but the RYGB group required less anti-hypertensive classes compared to the MT alone (Figure). The rate of non-dipping BP did not change significantly during the follow-up (RYGB: from 18/48 (37.5%) to 22/48 (45.8%); p=0.30; MT: from 16/33 (48.5%) to 15/33 (45.5%); p=0.80). In an exploratory analysis, the incidence of RH was similar at the baseline (RYGB 10% (5/50) and MT 16% (8/50); p=0.38). After 12 months, it changed significantly in the RYGB group: 0% (0/49) while remained stable in the MT group: 14.9% (7/47) (p<0.001).

Conclusions: RYGB significantly reduced anti-hypertensive medications while promoting similar 24-h BP profile and non-dipping BP status compared to the MT alone. RYGB may be an attractive strategy to reduce RH incidence in obese patients.

Effects of Bariatric Surgery in Obese Patients With Hypertension: The GATEWAY Randomized Trial (Gastric Bypass to Treat Obese Patients With Steady Hypertension)

BACKGROUND

Recent research efforts on bariatric surgery have focused on metabolic and diabetes mellitus resolution. Randomized trials designed to assess the impact of bariatric surgery in patients with obesity and hypertension are needed.

METHODS

In this randomized, single-center, nonblinded trial, we included patients with hypertension (using ≥2 medications at maximum doses or >2 at moderate doses) and a body mass index between 30.0 and 39.9 kg/m². Patients were randomized to Roux-en-Y gastric bypass plus medical therapy or medical therapy alone. The primary end point was reduction of ≥30% of the total number of antihypertensive medications while maintaining systolic and diastolic blood pressure <140 mm Hg and 90 mm Hg, respectively, at 12 months.

RESULTS

We included 100 patients (70% female, mean age 43.8±9.2 years, mean body mass index 36.9±2.7 kg/m2), and 96% completed follow-up. Reduction of ≥30% of the total number of antihypertensive medications while maintaining controlled blood pressure occurred in 41 of 49 patients from the gastric bypass group (83.7%) compared with 6 of 47 patients (12.8%) from the control group with a rate ratio of 6.6 (95% confidence interval, 3.1-14.0; P<0.001). Remission of hypertension was present in 25 of 49 (51%) and 22 of 48 (45.8%) patients randomized to gastric bypass, considering office and 24-hour ambulatory blood pressure monitoring, respectively, whereas no patient submitted to medical therapy was free of antihypertensive drugs at 12 months. A post hoc analysis for the primary end point considering the SPRINT (Systolic Blood Pressure Intervention Trial) target reached consistent results, with a rate ratio of 3.8 (95% confidence interval, 1.4-10.6; P=0.005). Eleven patients (22.4%) from the gastric bypass group and none in the control group were able to achieve SPRINT levels without antihypertensives. Waist circumference, body mass index, fasting plasma glucose, glycohemoglobin, low-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein, and 10-year Framingham risk score were lower in the gastric bypass than in the control group.

CONCLUSIONS

Bariatric surgery represents an effective strategy for blood pressure control in a broad population of patients with obesity and hypertension.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT01784848.

Effects of intermittent fasting on metabolism in men

This review analyzes the available literature on the impact of intermittent fasting (IF), a nutritional intervention, on different aspects of metabolism. The epidemic of metabolic disturbances, such as obesity, metabolic syndrome (MS), and diabetes mellitus type 2 has led to an increase in the prevalence of cardiovascular diseases, and affected patients might significantly benefit from modifications in nutritional habits. Recent experimental studies have elucidated some of the metabolic mechanisms involved with IF. Animal models have shown positive changes in glucose (lower plasma glucose and insulin levels) and in lipid metabolism (reduced visceral fat tissue and increased plasma adiponectin level), and an increased resistance to stress. Despite the limited number of samples studied, positive results have been reported on the impact of IF for human health. IF is reported to improve the lipid profile; to decrease inflammatory responses, reflected by changes in serum adipokine levels; and to change the expression of genes related to inflammatory response and other factors. Studies on obese individuals have shown that patient compliance was greater for IF than other traditional nutritional approaches (calorie restriction), and IF was found to be associated with low oxidative stress. Recent reports suggest that IF exerts a positive impact on the metabolic derangements commonly associated with cardiovascular diseases, and that it may be a viable and accessible intervention for most individuals. Therefore, further clinical studies are essential to test the effectiveness of IF in preventing and controlling metabolic and cardiovascular diseases.

Interleukin-6 produced in subcutaneous adipose tissue is linked to blood pressure control in septic patients

Cytokines are inflammatory mediators of major relevance during sepsis. Recent evidence shows that adipose tissue can produce many distinct cytokines under physiological and pathological conditions, but the role of cytokines produced in adipose tissue was not addressed in sepsis. In the present study the open-flow microperfusion (OFM) technique was used to investigate whether the cytokines produced in subcutaneous adipose tissue (SAT) of patients with severe sepsis correlate with clinical variables. Interstitial fluid effluent samples were collected using an OFM catheter inserted in the abdominal SAT of nine patients with severe sepsis. Blood samples were withdrawn concomitantly and interleukin-1beta (IL-1beta), IL-8, IL-6 and tumor necrosis factor alpha (TNF-alpha) were measured both in SAT effluent and serum samples. Different time profiles were registered for each cytokine. IL-1beta increased in a time-dependent manner, indicating a localized response against the catheter insertion. Interleukin-1beta, 6 and 8 were higher in SAT than in serum suggesting they were locally produced. Diastolic blood pressure (DBP) negatively correlated with IL-1beta, IL-6 and IL-8 in SAT indicating a possible interaction between adipose tissue inflammation and vascular tone regulation. A multiple regression analysis disclosed that mean DBP was significantly related to IL-6 concentrations in SAT (B=-43.9; R-square=0.82; P=0.002).

Assessment of different techniques for subcutaneous glucose monitoring in Type 1 diabetic patients during 'real-life' glucose excursions

AIMS

To compare the accuracy of two marketed subcutaneous glucose monitoring devices (Guardian RT, GRT; GlucoDay S, GDS) and standard microdialysis (CMA60; MD) in Type 1 diabetic patients.

METHODS

Seven male Type diabetic patients were investigated over a period of 26 h simulating real-life meal glucose excursions. Catheters of the three systems were inserted into subcutaneous adipose tissue of the abdominal region. For MD, interstitial fluid was sampled at 30- to 60-min intervals for offline glucose determination. Reference samples were taken at 15- to 60-min intervals. All three systems were prospectively calibrated to reference. Median differences, median absolute relative differences (MARD), median absolute differences (MAD), Bland-Altman plot and Clark Error Grid were used to determine accuracy.

RESULTS

Bland-Altman analysis indicated a mean glucose difference (2 standard deviations) between reference and interstitial glucose of -10.5 (41.8) % for GRT, 20.2 (55.9) % for GDS and 6.5 (35.2) % for MD, respectively. Overall MAD (interquartile range) was 1.07 (0.39; 2.04) mmol/l for GRT, 1.59 (0.54; 3.08) mmol/l for GDS and 0.76 (0.26; 1.58) mmol/l for MD. Overall MARD was 15.0 (5.6; 23.4) % (GRT), 19.7 (6.1; 37.6) % (GDS) and 8.7 (4.1; 18.3) % (MD), respectively. Total sensor failure occurred in two subjects using GRT and one subject using GDS.

CONCLUSIONS

The three investigated technologies had comparable performance. Whereas GRT underestimated actual blood glucose, GDS and MD overestimated blood glucose. Considerable deviations during daily life meal glucose excursions from reference glucose were observed for all three investigated technologies. Present technologies may require further improvement until individual data can lead to direct and automated generation of therapeutic advice in diabetes management.

Adipose tissue, inflammation and cardiovascular disease

Obesity has become a very frequent condition with important consequences for the health of affected individuals. Current evidence shows that the excess of adipose tissue as observed in obesity is responsible for secreting inflammatory mediators in a deregulated manner, thus inducing a chronic state of systemic low-grade inflammation that underlies the metabolic and cardiovascular outcomes in these populations. This article reviews the state of the art regarding mediators produced in the adipose tissue, their roles in the pathophysiology of obesity-associated insulin resistance and diabetes, and finally, tries to build a bridge between these mechanistically oriented insights and clinical practice.

Clinical evaluation of subcutaneous lactate measurement in patients after major cardiac surgery

Minimally invasive techniques to access subcutaneous adipose tissue for glucose monitoring are successfully applied in type1 diabetic and critically ill patients. During critical illness, the addition of a lactate sensor might enhance prognosis and early intervention. Our objective was to evaluate SAT as a site for lactate measurement in critically ill patients. In 40 patients after major cardiac surgery, arterial blood and SAT microdialysis samples were taken in hourly intervals. Lactate concentrations from SAT were prospectively calibrated to arterial blood. Analysis was based on comparison of absolute lactate concentrations (arterial blood vs. SAT) and on a 6-hour lactate trend analysis, to test whether changes of arterial lactate can be described by SAT lactate. Correlation between lactate readings from arterial blood vs. SAT was highly significant (r2 = 0.71, P < .001). Nevertheless, 42% of SAT lactate readings and 35% of the SAT lactate trends were not comparable to arterial blood. When a 6-hour stabilization period after catheter insertion was introduced, 5.5% of SAT readings and 41.6% of the SAT lactate trends remained incomparable to arterial blood. In conclusion, replacement of arterial blood lactate measurements by readings from SAT is associated with a substantial shortcoming in clinical predictability in patients after major cardiac surgery.

Subcutaneous adipose tissue exerts proinflammatory cytokines after minimal trauma in humans

Inflammatory cytokines released from adipose tissue play an important role in different pathological processes. In the present study, we investigated the inflammatory cytokine response of human subcutaneous adipose tissue (SAT) by applying the open-flow microperfusion technique. Four standard 18-gauge microperfusion catheters were inserted into periumbilical SAT of eight healthy male volunteers [29 +/- 3 yr, BMI 24.3 +/- 1.9 (mean +/- SD)]. SAT probe effluents were collected at 60-min intervals for 8 h after catheter insertion. Different perfusion fluids were used to measure the local effect of insulin and/or glucose on the cytokine response. SAT probe effluents were analyzed for IL-1beta, IL-6, CXCL8 (IL-8), and TNF-alpha. SAT concentrations of IL-1beta increased 100-fold from 1.0 +/- 0.2 pg/ml (mean +/- SE) to 101.5 +/- 23.2 pg/ml (P < 0.001) after 8 h. A 130-fold increase was observed for CXCL8, from 49 +/- 29 to 6,554 +/- 1,713 pg/ml (P < 0.001). Furthermore, a 20-fold increase of IL-6 was observed within the first 5 h (from 159 +/- 123 to 3,554 +/- 394 pg/ml; P < 0.001), and a significant decline to 2,154 +/- 216 pg/ml (P < 0.01) was seen thereafter. Finally, TNF-alpha increased from 1.4 +/- 0.6 to 2.5 +/- 0.5 pg/ml (P < 0.05) in hour 2 and remained stable thereafter. Local administration of insulin exerted a stimulatory effect on the inflammatory response of IL-6. In conclusion, SAT exerts a highly reproducible and consistent proinflammatory cytokine response after minimally invasive trauma caused by the insertion of a catheter in humans.

Physiological hyperinsulinemia has no detectable effect on access of macromolecules to insulin-sensitive tissues in healthy humans

OBJECTIVE

Physiologically elevated insulin concentrations promote access of macromolecules to skeletal muscle in dogs. We investigated whether insulin has a stimulating effect on the access of macromolecules to insulin-sensitive tissues in humans as well.

RESEARCH DESIGN AND METHODS

In a randomized, controlled trial, euglycemic-hyperinsulinemic clamp (1.2 mU x kg(-1) x min(-1) insulin) and saline control experiments were performed in 10 healthy volunteers (aged 27.5 +/- 4 years, BMI 22.6 +/- 1.6 kg/m(2)). Distribution and clearance parameters of inulin were determined in a whole-body approach, combining primed intravenous infusion of inulin with compartment modeling. Inulin kinetics were measured in serum using open-flow microperfusion in interstitial fluid of femoral skeletal muscle and subcutaneous adipose tissue.

RESULTS

Inulin kinetics in serum were best described using a three-compartment model incorporating a serum and a fast and a slow equilibrating compartment. Inulin kinetics in interstitial fluid of peripheral insulin-sensitive tissues were best represented by the slow equilibrating compartment. Serum and interstitial fluid inulin kinetics were comparable between the insulin and saline groups. Qualitative analysis of inulin kinetics was confirmed by model-derived distribution and clearance parameters of inulin. Physiological hyperinsulinemia (473 +/- 6 vs. 18 +/- 2 pmol/l for the insulin and saline group, respectively; P < 0.001) indicated no effect on distribution volume (98.2 +/- 6.2 vs. 102.5 +/- 5.7 ml/kg; NS) or exchange parameter (217.6 +/- 34.2 vs. 243.1 +/- 28.6 ml/min; NS) of inulin to peripheral insulin-sensitive tissues. All other parameters identified by the model were also comparable between the groups.

CONCLUSIONS

Our data suggest that in contrast to studies performed in dogs, insulin at physiological concentrations does not augment recruitment of insulin-sensitive tissues in healthy humans.