Left ventricular hypertrophy and QT interval in obesity and in hypertension: effects of weight loss and of normalisation of blood pressure

BACKGROUND: Left ventricular hypertrophy (LVH) and prolonged QT interval at ECG (QTc) are common in both obesity and arterial hypertension (AH), and are risk factors for cardiovascular disease and sudden death. METHODS: We compared the frequencies of LVH (ECG criteria) and QTc in obese-AH (n=41), in normotensive obese (n=75), in lean-AH (n=30), and in lean controls (n=68) comparable for age and sex; in obese patients, LVH and QTc were evaluated under basal conditions and 1 y later, that is, after a significant weight loss induced by bariatric surgery. RESULTS: LVH was more frequent, and QTc was longer, in obese-AH, in normotensive obese, and in lean-AH than in lean controls; after weight loss, frequency of LVH decreased in obese subjects becoming normotensive (n=87), not in obese subjects remaining hypertensive (n=29), while QTc decreased in all obese subjects. CONCLUSION: Weight loss can effectively reduce QTc; when concomitant AH disappears, weight loss can also reduce the prevalence of LVH. In obese patients remaining hypertensive, aggressive pharmacological treatment is therefore indicated to correct LVH.     

Obesity and COPD: Associated Symptoms,Health-related Quality of Life,and Medication Use

Background: There is little data about the combined effects of COPD and obesity. We compared dyspnea, health-related quality of life (HRQoL), exacerbations, and inhaled medication use among patients who are overweight and obese to those of normal weight with COPD. Methods: We performed secondary data analysis on 364 Veterans with COPD. We categorized subjects by body mass index (BMI). We assessed dyspnea using the Medical Research Council (MRC) dyspnea scale and HRQoL using the St. George's Respiratory Questionnaire. We identified treatment for an exacerbation and inhaled medication use in the past year. We used multiple logistic and linear regression models as appropriate, with adjustment for age, COPD severity, smoking status, and co-morbidities. Results: The majority of our population was male (n = 355, 98%) and either overweight (n = 115, 32%) or obese (n = 138, 38%). Obese and overweight subjects had better lung function (obese: mean FEV₁ 55.4% ±19.9% predicted, overweight: mean FEV₁ 50.0% ±20.4% predicted) than normal weight subjects (mean FEV₁ 44.2% ±19.4% predicted), yet obese subjects reported increased dyspnea [adjusted OR of MRC score ≥2 = 4.91 (95% CI 1.80, 13.39], poorer HRQoL, and were prescribed more inhaled medications than normal weight subjects. There was no difference in any outcome between overweight and normal weight patients. Conclusions: Despite having less severe lung disease, obese patients reported increased dyspnea and poorer HRQoL than normal weight patients. The greater number of inhaled medications prescribed for obese patients may represent overuse. Obese patients with COPD likely need alternative strategies for symptom control in addition to those currently recommended.     

Effect of weight loss on QTc dispersion in obese subjects.

OBJECTIVE: Increased QTc dispersion is a predictor for ventricular arrhythmias. The aim of this study was to investigate whether QTc dispersion decreases after weight loss program with diet and medical treatment. METHODS: Total 30 (24 women and 6 men, mean age: 44+/-8 years) obese subjects who lost at least 10% of their original weight after 12 week weight loss program were included in present study. Obesity was defined as > or =30 kg/m(2) of body mass index (BMI). Normal weight was defined as < or = 25 kg/m(2) of BMI. RESULTS: After 12 week weight loss program, BMI decreased from 42+/-5 kg/m(2) to 36+/-4 kg/m(2) (p<0.001) and mean weight of obese subjects decreased from 110+/-17 kg to 95+/-15 kg (p<0.001). The mean amount of weight loss was 14.5+/-5.0 kg (range 9-32 kg). The average percent of weight loss was 13% (10.0%-20.3%). Maximum QTc interval (from 446+/-19 ms to 433+/-27 ms, p=0.024) and QTc dispersion (from 66+/-18 ms to 52+/-25 ms, p=0.024) significantly decreased after weight loss program. A statistically significant correlation was found between decrease in level of QTc dispersion and amount of weight loss (r=0.487, p=0.007). CONCLUSION: Substantial weight loss in obese subjects is accompanied by significantly decreased QTc dispersion. The degree of QTc dispersion reduction is associated with amount of weight loss.     

Correlation of QT interval with disease activity in newly detected SLE patients at baseline and during flare

AimTo study correlation between QT interval parameters (QTc interval & QT dispersion) and disease activity (SLEDAI) in patients with systemic lupus erythematosus (SLE).MethodsThe study was done on 100 newly diagnosed patients with SLE and 100 age matched controls from January 2012 to December 2013. A standard 12 lead Electrocardiogram was obtained. QT interval was calculated from beginning of ‘q’ wave to end of T wave in lead II or lateral leads (V5, V6). QT dispersion was measured as the difference between maximum and minimum QT intervals. SLE disease activity was measured SLEDAI.ResultsEighty four patients had high disease activity. QTc was >440 msec in 51 patients and 6 controls. QTd was prolonged in 6 patients and 6 controls. The mean QTc interval among patients (463.30 ± 27.43 msec) was higher than in controls (397.24 ± 31.85 msec; p < 0.001). However the mean QTd among patients (44.40 + 20.61 msec) was similar to that in controls (39.2 + 17.7 msec). Difference of QTc values during severe flare from baseline QTc values was statistically significant (r = 0.863; Pearson's correlation coefficient).ConclusionsPatients with high disease activity have higher prevalence of QTc prolongation, QTc interval may be used as a surrogate marker for assessing disease activity in SLE.     

Long‐chain polyunsaturated fatty acid status in obesity: a systematic review and meta‐analysis

Long‐chain polyunsaturated fatty acid (LCPUFA) status has recently been related to the pathogenesis of obesity. Our aims were to systematically review observational studies investigating LCPUFA status from different blood compartments in overweight or obese subjects and to assess the relationship between LCPUFA profile and obesity. The Ovid MEDLINE, Scopus and Cochrane Library CENTRAL databases were searched from inception to January 2014. The meta‐analysis showed significant differences in the LCPUFA composition of total plasma lipids, plasma phospholipids and plasma cholesteryl esters between overweight or obese subjects and controls. Dihomo‐γ‐linolenic acid (DGLA) values were significantly higher in overweight or obese subjects compared with controls in all the investigated biomarkers. In addition, the DGLA/linoleic acid ratio (surrogate parameter for Δ6 desaturase activity) in plasma phospholipids was significantly elevated (mean difference [MD]: 0.05; 95% confidence interval [CI]: 0.02, 0.08; n = 280), while the arachidonic acid/DGLA ratio (surrogate parameter for Δ5 desaturase activity) was significantly decreased (MD: ?0.55; 95% CI: ?0.71, ?0.39; n = 347) in overweight or obese subjects compared with controls. The results of the present meta‐analysis confirm that LCPUFA profile is altered in obesity and suggest that the differences observed in desaturase activities may be responsible for the disturbed LCPUFA metabolism in obesity.     

An Evaluation of the Impact of Gender and Age on QT Dispersion in Healthy Subjects

Objectives: To determine if gender, age, and gender per age category, have an impact on QT and QTc dispersion in healthy volunteers. Methods: This study was undertaken in 150 patients (50 per age group, 75 males, 75 females). The age groups included young (20–40 years), middle‐aged (41–69 years) and elderly (> 70 years) subjects. The QT intervals on a 12 lead ECG were determined and Bazett's formula was used to derive the QTc intervals. The QT and QTc dispersion were determined by subtracting the shortest QTc interval from the longest on each 12‐lead recording. Results: Males had higher QT dispersion than females (50 ± 22 vs 42 ± 18 ms, P = 0.017) but QTc dispersion was not significantly changed. No significant differences were seen among the different age categories for QT or QTc dispersion. In elderly subjects, males had higher QT and QTc dispersion than females (54 ± 23 vs 42 ±15 ms, P = 0.039 and 63 ± 23.7 vs 48 ± 21 ms, P = 0.032, respectively). Conclusions: When evaluating the effect of gender in different age categories, elderly males have significantly greater QT and QTc dispersion than elderly female subjects. No other gender differences were noted for QT or QTc dispersion in the other two age categories. When evaluating a population of healthy volunteers, regardless of age, gender has an impact on QT dispersion but no significant interaction with QTc dispersion. Evaluating age without dividing the data by gender yields no significant differences in QT or QTc dispersion. A.N.E. 2001;6(2):129–133     

Obesity and iron deficiency: a quantitative meta‐analysis

Hypoferraemia (i.e. iron deficiency) was initially reported among obese individuals several decades ago; however, whether obesity and iron deficiency are correlated remains unclear. Here, we evaluated the putative association between obesity and iron deficiency by assessing the concentration of haematological iron markers and the risks associated with iron deficiency in both obese (including overweight) subjects and non‐overweight participants. We performed a systematic search in the databases PubMed and Embase for relevant research articles published through December 2014. A total of 26 cross‐sectional and case–control studies were analysed, comprising 13,393 overweight/obese individuals and 26,621 non‐overweight participants. Weighted or standardized mean differences of blood iron markers and odds ratio (OR) of iron deficiency were compared between the overweight/obese participants and the non‐overweight participants using a random‐effects model. Compared with the non‐overweight participants, the overweight/obese participants had lower serum iron concentrations (weighted mean difference [WMD]: ?8.37 μg dL^?1; 95% confidence interval [CI]: ?11.38 to ?5.36 μg dL^?1) and lower transferrin saturation percentages (WMD: 2.34%, 95% CI: ?3.29% to ?1.40%). Consistent with this finding, the overweight/obese participants had a significantly increased risk of iron deficiency (OR: 1.31; 95% CI: 1.01–1.68). Moreover, subgroup analyses revealed that the method used to diagnose iron deficiency can have a critical effect on the results of the association test; specifically, we found a significant correlation between iron deficiency and obesity in studies without a ferritin‐based diagnosis, but not in studies that used a ferritin‐based diagnosis. Based upon these findings, we concluded that obesity is significantly associated with iron deficiency, and we recommend early monitoring and treatment of iron deficiency in overweight and obese individuals. Future longitudinal studies will help to test whether causal relationship exists between obesity and iron deficiency.     

QT Dispersion and Mortality in the Elderly

Background: The prognostic value of QT interval dispersion measured from a standard 12‐lead electrocardiogram (ECG) in the general population is not well established. The purpose of the present study was primarily to assess the value of QT interval dispersion obtained from 12‐lead ECG in the prediction of total, cardiac, stroke, and cancer mortality in the elderly. Methods: A random population sample of community‐living elderly people (n = 330, age ≧; 65 years, mean 74 ±; 6 years) underwent a comprehensive clinical evaluation, laboratory tests, and 12‐lead ECG recordings. Results: By the end of the 10‐year follow‐up, 180 subjects (55%) had died and 150 (45%) were still alive. Heart rate corrected QT (QTc) dispersion had been longer in those who had died than in the survivors (75 ±; 32 ms vs 63 ±; 35 ms, P = 0.01). After adjustment for age and sex in the Cox proportional hazards model, prolonged QTc dispersion (≧; 70 msec) predicted all‐cause mortality (relative risk [RR] 1.38, 95% confidence interval [Cl] 1.02–1.86) and particularly stroke mortality (RR 2.7, 95% Cl 1.29–5.73), but not cardiac (RR 1.38, 95% Cl 0.87–2.18) or cancer (RR 1.51, 95% Cl 0.91–2.50) mortality. After adjustment for age, sex, body mass index, blood pressure, blood glucose and cholesterol concentrations, functional class, history of cerebrovascular disease, diabetes, smoking, previous myocardial infarction, angina pectoris, congestive heart failure, medication, left ventricular hypertrophy on ECG, presence of atrial fibrillation and R‐R interval, increased QTc dispersion still predicted stroke mortality (RR 3.21, 95% Cl 1.09–9.47), but not total mortality or mortality from other causes. The combination of increased QTc dispersion and left ventricular hypertrophy on ECG was a powerful independent predictor of stroke mortality in the present elderly population (RR 16.52, 95% Cl 3.37–80.89). QTcmin (the shortest QTc interval among the 12 leads of ECG) independently predicted total mortality (RR 1.0082, 95% Cl 1.0028–1.0136, P = 0.003), cardiac mortality (RR 1.0191, 95% Cl 1.0102–1.0281, P < 0.0001) and cancer mortality (RR 1.0162, 95% Cl 1.0049–1.0277, P = 0.005). Conclusions: Increased QTc dispersion yields independent information on the risk of dying from stroke among the elderly and its component, QTcmin, from the other causes of death. A.N.E. 2001; 6(3):183–192     

Association of weight gain with incident knee pain,stiffness, and functional difficulties: A longitudinal study

Objective

To examine the longitudinal association between significant weight change and change in knee symptoms (pain, stiffness, and function), and to determine whether the effects differ in those who are obese and those with osteoarthritis (OA).

Methods

Two hundred fifty subjects ranging from normal weight to obese (body mass index range 16.9–59.1 kg/m²) and no significant musculoskeletal disease were recruited from the general community and weight loss clinics and organizations. Seventy‐eight percent were followed at ～2 years. Weight, height, and knee symptoms (using the Western Ontario and McMaster Universities Osteoarthritis Index) were assessed at baseline and followup. Any weight loss methods were recorded.

Results

Thirty percent of subjects lost ≥5% of baseline weight, 56% of subjects' weight remained stable (loss or gain of <5% of baseline weight), and 14% of subjects gained ≥5% of baseline weight. Using estimated marginal means, weight gain was associated with worsening pain (mean 27.1 mm; 95% confidence interval [95% CI] ?1.1, 55.2), stiffness (mean 18.4 mm; 95% CI 1.5, 35.3), and function (mean 99.3 mm; 95% CI 4.0, 194.6) compared to stable weight. Weight loss was associated with reduced pain (mean ?22.4 mm; 95% CI ?44.4, ?0.3), stiffness (mean ?15.3 mm; 95% CI ?28.50, ?2.0), and function (mean ?73.2 mm; 95% CI ?147.9, 1.3) compared to stable weight.

Conclusion

Weight gain was associated with adverse effects on knee symptoms, particularly in those who are obese and who have OA. Although losing weight is potentially beneficial for symptom improvement, the effects were more modest. Avoiding weight gain is important in managing knee symptoms.

     

Effect of orlistat on glycaemic control in overweight and obese patients with type 2 diabetes mellitus: a systematic review and meta‐analysis of randomized controlled trials

Orlistat is an effective adjunctive treatment to lifestyle modifications in the treatment of obesity. While the majority of current evidence is on the effect of orlistat in obese patients without diabetes, some studies suggest that patients who are obese and have diabetes mellitus lose more weight and have greater improvements in diabetic outcomes when treated with orlistat plus a lifestyle intervention than when treated by lifestyle interventions alone. The aim of this study was to review the evidence of the effects of orlistat on glycaemic control in overweight and obese patients with type 2 diabetes. A systematic review of randomized controlled trials of orlistat in people with type 2 diabetes reporting diabetes outcomes in studies published between January 1990 and September 2013 was conducted. We searched for articles published in English in MEDLINE and EMBASE. Inclusion criteria included all randomized controlled trials of orlistat carried out on adult participants with a body mass index of 25 kg m^?2 or over diagnosed with type 2 diabetes, which reported weight change and at least one diabetic outcome. A total of 765 articles were identified out of which 12 fulfilled the inclusion criteria. The overall mean weight reduction (3, 6 and 12 months) in the orlistat group was ?4.25 kg (95% CI: ?4.5 to ?3.9 kg). The mean weight difference between treatment and control groups was ?2.10 kg (95% CI: ?2.3 to ?1.8 kg, P < 0.001), the mean HbA1c difference was ?6.12 mmol mol^?1 (95% CI: ?10.3 to ?1.9 mmol mol^?1, P < 0.004) and the mean fasting blood glucose difference was ?1.16 mmol L^?1 (95% CI: ?1.4 to ?0.8 mmol L^?1, P < 0.001). Treatment with orlistat plus lifestyle intervention resulted in significantly greater weight loss and improved glycaemic control in overweight and obese patients with type 2 diabetes compared with lifestyle intervention alone.     

Effect of weight loss after bariatric surgery on left ventricular mass and ventricular repolarization in normotensive morbidly obese patients

To assess the effect of weight loss on ventricular repolarization in morbidly obese patients, 39 normotensive subjects whose baseline body mass indexes were ≥40 kg/m(2) before weight loss from bariatric surgery were studied. All patients were free of underlying organic heart disease, heart failure, and conditions that might affect ventricular repolarization. Twelve-lead electrocardiography and transthoracic echocardiography were performed just before surgery and at the nadir of postoperative weight loss. The corrected QT interval (QTc) was derived using Bazett's formula. QTc dispersion was calculated by subtracting the minimum from the maximum QTc on the 12-lead electrocardiogram. Echocardiographic left ventricular (LV) mass was indexed to height(2.7). The mean body mass index decreased from 42.8 ± 2.1 to 31.9 ± 2.2 kg/m(2) (p <0.0005). For the entire group, weight loss was associated with significant reductions in mean QTc (from 428.7 ± 18.5 to 410.5 ± 11.9 ms, p <0.0001) and mean QTc dispersion (from 44.1 ± 11.2 to 33.2 ± 3.3 ms, p <0.0005). Mean QTc and QTc dispersion decreased significantly with weight loss in patients with LV hypertrophy but not in subjects without LV hypertrophy. Multivariate analysis identified pre-weight loss LV mass/height(2.7) as the most important predictor of pre-weight loss QTc and QTc dispersion and also identified weight loss-induced change in LV mass/height(2.7) as the most important predictor of weight loss-induced changes in QTc and QTc dispersion. In conclusion, LV hypertrophy is a key determinant of QTc and QTc dispersion in normotensive morbidly obese patients. Regression of LV hypertrophy associated with weight loss decreases QTc and QTc dispersion.     

A Cross-Sectional Study Examining Australian General Practitioners’ Identification of Overweight and Obese Patients

BACKGROUND

Overweight and obese patients attempt weight loss when advised to do so by their physicians; however, only a small proportion of these patients report receiving such advice. One reason may be that physicians do not identify their overweight and obese patients.

OBJECTIVES

We aimed to determine the extent that Australian general practitioners (GP) recognise overweight or obesity in their patients, and to explore patient and GP characteristics associated with non-detection of overweight and obesity.

METHODS

Consenting adult patients (n?=?1,111) reported weight, height, demographics and health conditions using a touchscreen computer. GPs (n?=?51) completed hard-copy questionnaires indicating whether their patients were overweight or obese. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for GP detection, using patient self-reported weight and height as the criterion measure for overweight and obesity. For a subsample of patients (n?=?107), we did a sensitivity analysis with patient-measured weight and height. We conducted an adjusted, multivariable logistic regression to explore characteristics associated with non-detection, using random effects to adjust for correlation within GPs.

RESULTS

Sensitivity for GP assessment was 63 % [95 % CI 57–69 %], specificity 89 % [95 % CI 85–92 %], PPV 87 % [95 % CI 83–90 %] and NPV 69 % [95 % CI 65–72 %]. Sensitivity increased by 3 % and specificity was unchanged in the sensitivity analysis. Men (OR: 1.7 [95 % CI 1.1–2.7]), patients without high blood pressure (OR: 1.8 [95 % CI 1.2–2.8]) and without type 2 diabetes (OR: 2.4 [95 % CI 1.2–8.0]) had higher odds of non-detection. Individuals with obesity (OR: 0.1 [95 % CI 0.07–0.2]) or diploma-level education (OR: 0.3 [95%CI 0.1–0.6]) had lower odds of not being identified. No GP characteristics were associated with non-detection of overweight or obesity.

CONCLUSIONS

GPs missed identifying a substantial proportion of overweight and obese patients. Strategies to support GPs in identifying their overweight or obese patients need to be implemented.     

Predictive factors of ventricular fibrillation triggered by pause-dependent torsades de pointes associated with acquired long QT interval: role of QT dispersion and left ventricular function

INTRODUCTION: Death due to acquired torsades de pointes usually is caused by ventricular fibrillation (VF), but the contributing factors to VF triggered by pause-dependent torsades de pointes are not understood. METHODS AND RESULTS: We evaluated 91 patients who fulfilled four criteria: (1) pause-dependent torsades de pointes; (2) prolonged QT interval and/or corrected QT (QTc) (>0.44 sec); (3) long-short initiation sequence; and (4) conditions known to induce pause-dependent torsades de pointes. There were 38 patients with a documented VF (group I) and 53 without VF (group II). Absolute and relative dispersions of QT and QTc were calculated based on the 12-lead standard ECG. Group I differed from group II with regard to myocardial infarction history (32% vs 13%; P = 0.035), left ventricular ejection fraction (44% +/- 14% vs 65% +/- 9%; P < 0.0001), presence of structural heart disease (100% vs 20.8%; P < 0.0001), QT mean (591 +/- 73 msec vs 514 +/- 78 msec; P < 0.0001), QTc mean (563 +/- 76 msec vs 508 +/- 90 msec; P = 0.002), absolute QT dispersion (166 +/- 56 msec vs 84 +/- 49 msec; P < 0.0001), relative QT dispersion (9.9% +/- 3.5% vs 6.3% +/- 3.2%; P < 0.0001), absolute QTc dispersion (158 +/- 57 msec vs 81 +/- 44 msec; P < 0.0001), and relative QTc dispersion (9.9% +/- 3.6% vs 6.2% +/- 3%; P < 0.0001). Multiple regression analysis showed that ejection fraction (P = 0.0001), presence of structural heart disease (P < 0.0001), and relative QTc dispersion (P = 0.038) were the only independent predictors of VF. CONCLUSION: Left ventricular function, presence of structural heart disease, and QTc relative dispersion should be evaluated carefully in patients with conditions susceptible to inducing torsades de pointes.     

Patterns of QT Dispersion in Athletic and Hypertensive Left Ventricular Hypertrophy

Objective: The objective of this article is to assess whether left ventricular hypertrophy (LVH) due to physical training or of hypertensive patients shows similarities in QT length and QT dispersion. Methods: A total of 51 subjects were studied: 17 essential hypertensive patients (27.7 ± 5.6 years), 17 athletes involved in agonistic activity (canoeing) (24.8 ± 6.1 years), and 17 normotensive healthy subjects as control group (24.8 ± 3.6 years). The testing protocol consisted of (1) clinic BP measurement, (2) echocardiography, (3) 12‐lead electrocardiographic examination (QT max, QTc max, QT min, QTc min, ΔQT, ΔQTc). Results: There were no significant differences between the body surface area, height, and age of the three groups. Clinic blood pressure was higher in hypertensives (146.5 ± 45.2/93.5 ± 4.9 mmHg) versus athletes (120.9 ± 10.8/77.1 ± 6.0 mmHg) and controls (123.5 ± 4.8/78.8 ± 2.9 mmHg) by definition. Indexed left ventricular mass (LVM/BSA) was significantly greater in both athletes (148.9 ± 21.1 g/m²) and hypertensives (117.1 ± 15.2 g/m²) versus controls (81.1 ± 14.5 g/m²; P < 0.01), there being no statistical difference among them. LVH (LVMI > 125 g/m²) was observed in all athletes, while the prevalence in hypertensives was 50%. In spite of this large difference in cardiac structure there were no significant differences in QT parameters between athletes and the control group, while hypertensive patients showed a significant increase in QT dispersion versus the two other groups (ΔQT 82 ± 2.1, 48 ± 1.3, 49 ± 2.3 ms; P < 0.01; ΔQTc 88 ± 2.0, 47 ± 1.4, 54 ± 2.7; P < 0.01). Conclusions: LVH induced by physical training activity is not associated with an increase in QT dispersion, whereas pathological increase in LVM secondary to hypertension is accompanied by an increased QT dispersion.     

Relationship between infarction location and size to QT dispersion in patients with chronic myocardial infarction

The relationship between the location and size of an infarction and QT dispersion was investigated in 84 Japanese patients with chronic myocardial infarction (54 with anteroseptal infarction and 30 with inferior infarction). The control group consisted of 23 subjects without ischemic heart disease (13 normal subjects and 10 hypertensive patients). Corrected QT dispersion (maximum corrected QT interval minus minimum corrected QT interval: QTc dispersion), was significantly larger in the anterior infarction group than in the control group (69.9+/-21.5 msec vs 53.0+/-17.6 msec), while the inferior infarction group showed no significant difference from control subjects. QTc dispersion was significantly greater in the patients with large anterior infarcts than in those with small anterior infarcts (80.5+/-20.5 msec vs 61.9+/-18.8 msec). In patients with chronic myocardial infarction, QT dispersion is influenced by the infarct location and size. Accordingly, interpretation of QT dispersion data should take these factors into consideration.     

Sympathomimetic infusion and cardiac repolarization: the normative effects of epinephrine and isoproterenol in healthy subjects

Introduction: Catecholamines are known to affect cardiac repolarization, and provocation with either isoproterenol or epinephrine has been proposed as a tool for uncovering latent repolarization abnormalities. This study systematically compares the effects of isoproterenol and epinephrine infusions on QT interval (QT), T waves and U waves in normal subjects.
Methods and Results: Twenty-four normal subjects (29 ± 8 years) were evaluated during graded infusions of up to 0.30 μg/kg/minute epinephrine and 5.0 μg/minute isoproterenol. Heart rates at peak doses were 81 ± 13 bpm at 0.28 ± 0.04 μg/kg/minute epinephrine and 104 ± 5 bpm at 2.4 μg/minute isoproterenol. The longest absolute QT increase was 4 ± 5 msec above baseline during isoproterenol (P < 0.001) and 12 ± 23 msec during epinephrine (P = 0.07), while the longest corrected QT interval (QTc) increase was 67 ± 28 msec (P < 0.0001) and 79 ± 40 msec (P < 0.0001) above baseline during isoproterenol and epinephrine, respectively (P = 0.12 for difference). There was a 2-fold increase in U-wave amplitude during each intervention (P < 0.001). The specificity of paradoxical QT prolongation (≥30 msec at 0.05 μg/kg/minute or ≥35 msec at 0.10 μg/kg/minute epinephrine) and an increase in QTc ≥600 msec at any dose epinephrine were 100%. However, the specificity of other proposed criteria that utilized QTc measurement (≥30 msec at 0.10 μg/kg/minute or ≥65 msec at any dose) was poor whether all leads or only lead II were assessed.
Conclusion: Both epinephrine and isoproterenol are associated with QTc prolongation and amplification of the U wave in normal subjects. The specificity of proposed criteria for epinephrine provocation in diagnosis of the long-QT syndrome is variable; however, paradoxical QT prolongation at low-dose epinephrine or a QTc ≥600 msec is highly specific.     

Weight loss effects of circuit training interventions: A systematic review and meta‐analysis

This meta‐analysis aimed to assess the weight loss effects of circuit training interventions in adults. A computerized search was conducted using the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE online databases. The analysis was restricted to randomized controlled trials that evaluated the effects of circuit training interventions on body weight and body mass index in adults aged 18 years or older. Meta‐analyses were conducted using the random‐effect model to estimate the weighted mean difference (WMD) with 95% confidence interval (CI). Nine randomized controlled trials (837 participants) were included. Significant intervention effects were identified for body weight (WMD = ?3.81 kg, 95% CI ?5.60 to ?2.02) and body mass index (WMD = ?1.77 kg/m², 95% CI ?2.49 to ?1.04). Subgroup analysis by body mass index status showed that the intervention effect was significant only in participants with obesity or overweight (obesity: WMD = ?5.15 kg, 95% CI ?8.81 to ?1.50 and overweight: WMD = ?3.89 kg, 95% CI ?7.00 to ?0.77, respectively) but not in those with normal weight. Current evidence suggests that circuit training effectively reduces body weight and body mass index in adults with overweight and obesity.     

Assessment of QT intervals and prevalence of short QT syndrome in Japan

BACKGROUND: Long QT syndrome causes ventricular tachyarrhythmias and sudden death. Recently, a short QT interval has also been shown to be associated with an increased risk of tachyarrhythmia and sudden death. However, the prevalence of short QT syndrome is not well-known. HYPOTHESIS: The aim of this study was to assess the distribution of corrected QT intervals (QTc) and prevalence of short QT syndrome. METHODS: This study comprised 12,149 consecutive subjects who received a consultation at Kanazawa University Hospital, Kanazawa, Japan, and had an electrocardiogram (ECG) between February 2003 and May 2004. Of these subjects, 1,165 subjects were excluded because of inappropriate ECGs, while the remaining 10,984 subjects had their last-recorded ECGs analyzed. RESULTS: The QTc values showed a nearly normal distribution (408 +/- 25 msec(1/2)), and were significantly longer in females (412 +/- 24 msec(1/2)) than in males (404 +/- 25 msec(1/2)) (p < 0.05). Among 5,511 males, 69 subjects (1.25%) exhibited QTc < 354 msec(1/2) (2 standard deviations [SDs] below the mean in males), and among 5,473 females, 89 subjects (1.63%) exhibited QTc < 364 msec(1/2) (2 SDs below the mean in females). Only 3 subjects (0.03% in all subjects and 0.05% in males) exhibited QTc < 300 msec(1/2), however, none had clinical symptoms of short QT syndrome. CONCLUSIONS: Short QT syndrome may be very rare.     

The role of childhood BMI in predicting early adulthood dysglycemia: Tehran lipid and glucose study

Background and AimIncreased adiposity is associated with insulin resistance and glycemic disturbances. We aimed to determine whether childhood overweight or obesity are independent factors in predicting adulthood dysglycemia (prediabetes or type 2 diabetes).Methods and ResultsIn this population-based cohort study, 1290 normoglycemic subjects aged 3–11 years were followed for incidence of dysglycemia. Cox-proportional hazard models were employed to evaluate the association of obesity and overweight with incidence of dysglycemia by adjustments for age, sex, parental risk factors and baseline individual risk factors.The participants, with a mean age of 7.7 ± 2.5 years, were followed for a median of 14.9 years. During follow up, 158 subjects developed dysglycemia (18 type 2 diabetes, 140 prediabetes), contributing to a total cumulative incidence of 24.7%. The unadjusted HR for developing adult dysglycemia were 1.6 (95% CI; 1.0–2.4) and 1.7 (95% CI; 1.0–3.0) in overweight and obese children, respectively. Further adjustments for age, sex, parental risk factors and baseline individual risk factors changed the results in both overweight and obese children.ConclusionThese findings show that overweight or obesity in childhood have no independent role for developing adulthood dysglycemia.     

A retrospective study of maternal and neonatal outcomes in overweight and obese women with gestational diabetes mellitus

In pregnant women, obesity is a risk factor for multiple adverse pregnancy outcomes, including gestational diabetes mellitus (GDM), preeclampsia, and preterm birth. The aim of this study was to determine the effects of pre-pregnancy body mass index (BMI) on maternal and neonatal outcomes in women with GDM. A retrospective study of 5010 patients with GDM in 11 provinces in China was performed in 2011. Participants were divided into three groups based on BMI as follows: a normal weight group (BMI 18.5–23.9 kg/m²), an overweight group (BMI 24–27.9 kg/m²), and an obese group (BMI ≥28.0 kg/m²). Maternal baseline characteristics and pregnancy and neonatal outcomes were compared between the groups. Multiple logistic regression analysis was used to explore the relationships between BMI and the risk of adverse outcomes. Of the 5010 GDM patients, 2879 subjects were from north China and 2131 were from south China. Women in the normal weight group gained more weight during pregnancy compared with the overweight and obese GDM patients. Women in the overweight and obese groups had increased odds of hypertension during pregnancy (adjusted odds ratio (AOR)?=?1.50, 95 % confidence interval (CI)?=?1.31–1.76 and AOR?=?2.12, 95 % CI?=?1.84–3.16). The AORs for macrosomia in the overweight and obese groups were 1.46 (95 % CI?=?1.16–1.69) and 1.94 (95 % CI?=?1.31–2.98), respectively. The relative risk of delivering a baby with an Apgar score <7 at 5 min was significantly higher in women who were obese (AOR?=?2.11, 95 % CI?=?1.26–2.85) before pregnancy compared with normal weight women. Compared with the normal weight subjects, the incidence of cesarean section and emergency cesarean section among overweight and obese women with GDM was significantly higher (P?<?0.001). Overall, overweight and obese women with GDM have an increased risk of adverse outcomes, including hypertension during pregnancy, macrosomic infants, infants with low Apgar scores, and the need for an emergency cesarean section. More attention should be paid to GDM women who are obese because they are at risk for multiple adverse outcomes.