Cardiometabolic risk improvement in response to a 3-yr lifestyle modification program in men: contribution of improved cardiorespiratory fitness vs. weight loss

Effects of 1,144 km of road cycling performed in 7 days: a cardiometabolic imaging study

This cardiometabolic imaging study was designed to document the adaptation of middle-aged recreational cyclists to a large exercise prescription not aiming at weight loss. Eleven middle-aged recreational male cyclists traveled 1,144 km over seven consecutive days. A comprehensive cardiometabolic profile including visceral and ectopic adiposity assessed by magnetic resonance imaging was obtained at baseline and following the exercise week. Cardiorespiratory fitness (CRF) was measured using maximal cardiopulmonary exercise testing. During the week, heart rate was monitored to calculate individual energy expenditure. Baseline characteristics of cyclists were compared with 86 healthy males in the same age range. Cyclists presented higher baseline CRF (+9.2 mL/kg/min, P < 0.0001) and lower subcutaneous (-56.2 mL, P < 0.05) and liver (-3.3%, P < 0.05) fat compared with the reference group. Despite the large energy expenditure during the cycling week, the increase in energy intake limited decreases in body weight (-0.8 ± 0.9 kg, P < 0.05) and body mass index (-0.3 ± 0.3 kg/m2, P < 0.05). Loss of fat mass (-1.5 ± 1.0 kg, P < 0.001) and a trend toward an increased lean mass (+0.8 ± 1.2 kg, P < 0.07) were observed. Visceral adiposity (-14.1 ± 14.2 mL, P < 0.01) and waist circumference (-3.2 ± 1.7 cm, P < 0.0001) decreased, whereas subcutaneous (-2.7 ± 5.1 mL, NS), liver (-0.5 ± 0.9%, NS), and cardiac (-0.3 ± 2.3 mL, NS) fat remained unchanged. This cardiometabolic imaging study documents middle-aged recreational cyclists' subcutaneous and visceral adiposity as well as cardiac and liver fat responses to a large volume of endurance exercise despite an increase in energy intake aimed at limiting weight loss.NEW & NOTEWORTHY Even when being accompanied by a substantial increase in energy intake to compensate energy expenditure and limit weight loss, a large volume of endurance exercise performed within a short period of time is associated with a significant reduction in visceral adiposity. High cardiorespiratory fitness is associated with low levels of liver fat in middle-aged males.

Long-Term Improvement in Cardiorespiratory Fitness Ameliorates Insulin Sensitivity beyond Changes in Visceral/Ectopic Fat among Men with Visceral Obesity

The SYNERGIE study documented the effects on cardiometabolic risk (CMR) indices of a 1-year lifestyle intervention targeting physical activity (PA) and diet followed by a 2-year maintenance period in men with visceral obesity. Improvements in CMR markers and a decrease in low-attenuation muscle (LAM) area were observed after 1 year. Despite a rebound in visceral adipose tissue (VAT) during the maintenance period, insulin resistance (IR) improved. We tested the hypothesis that variations in cardiorespiratory fitness (CRF) and LAM could explain the long-term improvement in IR. A health (n = 88; mean age 49.0 ± 8.2 years) and fitness (n = 72) evaluation was performed at 0, 1, and 3 years. Participants were classified into two groups based on their CRF response over the maintenance period (worsening: CRF- vs. maintenance/improvement: CRF+). During the maintenance period, changes in the psoas and core LAM areas correlated with changes in IR (r = 0.27; p < 0.05 and r = 0.34; p < 0.005) and changes in CRF (r = -0.31; p < 0.01 and r = -0.30; p < 0.05). IR improved in the CRF+ group (p < 0.05) but remained stable in the CRF- group. Men in the CRF+ group regained half of the changes in VAT volume and LAM at the psoas and mid-thigh compared to the CRF- group (p < 0.05). These results support the importance of targeting VAT and CRF/PA for the long-term management of CMR in men with visceral obesity.

Phenotyping obesity: A focus on metabolically healthy obesity and metabolically unhealthy normal weight

Over the past 4 decades, research has shown that having a normal body weight does not automatically imply preserved metabolic health and a considerable number of lean individuals harbour metabolic abnormalities typically associated with obesity. Conversely, excess adiposity does not always equate with an abnormal metabolic profile. In fact, evidence exists for the presence of a metabolically unhealthy normal weight (MUHNW) and a metabolically healthy obese (MHO) phenotype. It has become increasingly recognised that different fat depots exert different effects on the metabolic profile of each individual by virtue of their location, structure and function, giving rise to these different body composition phenotypes. Furthermore, other factors have been implicated in the aetiopathogenesis of the body composition phenotypes, including genetics, ethnicity, age and lifestyle/behavioural factors. Even though to date both MHO and MUHNW have been widely investigated and documented in the literature, studies report different outcomes on long-term cardiometabolic morbidity and mortality. Future large-scale, observational and population-based studies are required for better profiling of these phenotypes as well as to further elucidate the pathophysiological role of the adipocyte in the onset of metabolic disorders to allow for better risk stratification and a personalised treatment paradigm.

Overweight, Obesity, and CVD Risk: a Focus on Visceral/Ectopic Fat

PURPOSE OF REVIEW

Despite its prevalence and well-documented impact on population health, obesity has not emerged as a strong independent risk factor for cardiovascular disease after control for intermediate risk factors. The purpose of this brief narrative review is to highlight results from imaging studies that have not only documented the remarkable heterogeneity of body fat topography but also the importance of visceral adiposity as a key body fat depot associated with cardiovascular disease risk and type 2 diabetes.

RECENT FINDINGS

Simple tools are also discussed in order to refine cardiometabolic risk assessment in persons with overweight/obesity. It is proposed that four lifestyle vital signs should be considered in clinical practice to improve discrimination of health risk in individuals with overweight/obesity: waist circumference as a simple marker of abdominal adiposity, cardiorespiratory fitness, overall diet quality, and level of reported physical activity. Heterogeneity of obesity is proposed as an example of a condition that would benefit from a precision lifestyle medicine approach.

Changes in Body Weight and Concurrent Changes in Cardiovascular Risk Profiles in Community Residents in Japan: the Hisayama Study

AIM

We investigated the influence of weight change on concurrent changes in predicted cardiovascular disease (CVD) risk and individual CVD risk factors over time.

METHODS

A total of 2,140 community-dwellers aged 40-74 years participated in both 2002 and 2007 health examinations. Obesity was defined as body mass index ≥ 25 kg/m2. Weight trajectories were classified as: "stable obese" (obese at both examinations), "obese to nonobese" (obese in 2002 but nonobese in 2007), "nonobese to obese" (nonobese in 2002 but obese in 2007), or "stable nonobese" (nonobese at both examinations). We compared changes in the model-predicted risk for CVD and individual CVD risk factors across weight-change categories.

RESULTS

The predicted risk for CVD increased during 5 years in all groups; the increment in the predicted risk for CVD was smallest in the obese to nonobese participants and steepest in the nonobese to obese subjects. Compared with the stable obese participants, the obese to nonobese participants had greater favorable changes in waist circumferences, blood pressure, fasting plasma glucose, serum high-density lipoprotein cholesterol, serum triglycerides, and liver enzymes. For all these parameters, opposite trends were observed when comparing the nonobese to obese participants with the stable nonobese group.

CONCLUSIONS

We demonstrated the favorable association of losing weight in obese people and avoiding excessive weight gain in nonobese people with global risk of future CVD and individual CVD risk factors in a real-world setting. The findings could improve behavioral lifestyle interventions that provide information on the health consequences of weight change at health checkups.

Adipokines Profile and Inflammation Biomarkers in Prepubertal Population with Obesity and Healthy Metabolic State

(1) Background and aims: Obesity and high body max index (BMI) have been linked to elevated levels of inflammation serum markers such as C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), adiponectin, and resistin. It has been described that adipose tissue presents a high production and secretion of these diverse pro-inflammatory molecules, which may have local effects on the physiology of the fat cell and also systemic effects on other organs. Our aim was to evaluate the impact that lifestyle modifications, following a Mediterranean Diet (MedDiet) program and physical activity (PA) training, would have on inflammatory biomarkers in a metabolically healthy prepubertal population with obesity (MHOPp) from Malaga (Andalusia, Spain). (2) Methods: 144 MHOPp subjects (aged 5–9 years) were included in this study as they met ≤1 of the following criteria: waist circumference and blood pressure ≥ 90 percentile, triglycerides > 90 mg/dL, high-density lipoprotein cholesterol (HDL-c) < 40 mg/dL, or impaired fasting glucose (≥100 md/dL). Selected subjects followed a personalized intensive lifestyle modification. Anthropometric measurements, inflammation biomarkers, and adipokine profile were analyzed after 12 and 24 months of intervention. (3) Results: 144 MHOPp participants (75 boys—52% and 69 girls—48%; p = 0.62), who were 7.8 ± 1.4 years old and had a BMI 24.6 ± 3.3 kg/m², were included in the study. After 24 months of MedDiet and daily PA, a significant decrease in body weight (−0.5 ± 0.2 SD units; p < 0.0001) and BMI (−0.7 ± 0.2 SD units; p < 0.0001) was observed in the total population with respect to baseline. Serum inflammatory biomarkers (IL-6, TNF-alpha, and CRP) after 24 months of intervention were significantly reduced. Adipokine profile (adiponectin and resistin) did not improve with the intervention, as adiponectin levels significantly decreased and resistin levels increased in all the population. Inflammatory biomarkers and adipokine profile had a significant correlation with anthropometric parameters, body composition, and physical activity. (4) Conclusions: After 24 months of lifestyle modification, our MHOPp reduced their Z-score of BMI, leading to an improvement of inflammatory biomarkers but inducing deterioration in the adipokine profile, which does not improve with MedDiet and physical activity intervention. An adequate education within the family about healthier habits is necessary to prevent and reduce an excessive increase in obesity in childhood.

Effectiveness of Lifestyle Interventions in an Active Duty Air Force Population

PURPOSE

To examine the effectiveness of 3 lifestyle intervention programs in an active duty military population.

DESIGN

Experimental design with stratified random assignment to 1 of 3 intervention groups. Measures were taken at baseline, 3 months and 6 months.

SETTING

A Military Treatment Facility in the western U.S.

SUBJECTS/INTERVENTION

122 active duty service members were enrolled and randomly assigned to 1 of 3 lifestyle intervention programs: the Diabetes Prevention Program-Group Lifestyle Balance (DPP-GLB), the Better Body Better Life (BBBL) program or the Fitness Improvement Program (FIP).

MEASURES

weight, abdominal circumference, lipid and HbA1c levels, physical activity, and well-being as measured by the RAND SF-36 questionnaire.

ANALYSIS

Statistical analyses were performed to assess changes over time.

RESULTS

83 participants completed the study (BBBL N = 23, FIP N = 30, DPP-GLB N = 30). The DPP-GLB participants had statistically significant decreases in weight (-3.1 pounds, p = .01) and abdominal circumference (-0.9 inches; p = .01) over time. HbA1c was also significantly lower in this group at 6 months compared to baseline (p = .036). There were no statistically significant changes in weight, abdominal circumference, or HbA1c in the FIP or BBBL groups. No significant changes were observed in lipids in any of the groups.

CONCLUSION

Results from this study indicate that the DPP-GLB program may be effective in reducing weight, abdominal circumference, and HbA1c in an active duty U.S. military population.

From famine to therapeutic weight loss: Hunger, psychological responses, and energy balance-related behaviors

Understanding physiological and behavioral responses to energy imbalances is important for the management of overweight/obesity and undernutrition. Changes in body composition and physiological functions associated with energy imbalances provide the structural and functional context in which to consider psychological and behavioral responses. Compensatory changes in physiology and behavior are more pronounced in response to negative than positive energy balances. The physiological and psychological impact of weight loss (WL) occur on a continuum determined by (i) the degree of energy deficit (ED), (ii) its duration, (iii) body composition at the onset of the energy deficit, and (iv) the psychosocial environment in which it occurs. Therapeutic WL and famine/semistarvation both involve prolonged EDs, which are sometimes similar in magnitude. The key differences are that (i) the body mass index (BMI) of most famine victims is lower at the onset of the ED, (ii) therapeutic WL is intentional and (iii) famines are typically longer in duration (partly due to the voluntary nature of therapeutic WL and disengagement with WL interventions). The changes in psychological outcomes, motivation to eat, and energy intake in therapeutic WL are often modest (bearing in mind the nature of the measures used) and can be difficult to detect but are quantitatively significant over time. As WL progresses, these changes become more marked. It appears that extensive WL beyond 10%-20% in lean individuals has profound effects on body composition and physiological function. At this level of WL, there is a marked erosion of psychological functioning, which appears to run in parallel to WL. Psychological resources dwindle and become increasingly focused on alleviating escalating hunger and food seeking behavior. Functional changes in fat-free mass, characterized by catabolism of skeletal muscle and organs may be involved in the drive to eat associated with semistarvation. Higher levels of body fat mass may act as a buffer to protect fat-free mass, functional integrity and limit compensatory changes in energy balance behaviors. The increase in appetite that accompanies therapeutic WL appears to be very different to the intense and all-consuming drive to eat that occurs during prolonged semistarvation. The mechanisms may also differ but are not well understood, and longitudinal comparisons of the relationship between body structure, function, and behavior in response to differing EDs in those with higher and lower BMIs are currently lacking.

Visceral adiposity and liver fat as mediators of the association between cardiorespiratory fitness and plasma glucose-insulin homeostasis

Cardiorespiratory fitness (CRF) is positively associated with insulin sensitivity, whereas excessive levels of visceral adipose tissue (AT) and liver fat (LF) are both associated with insulin resistance and impaired plasma glucose-insulin homeostasis. To what extent levels of visceral AT and LF content contribute to the relationship between CRF and indices of plasma glucose-insulin homeostasis is uncertain. Our objective was to explore the interactions among CRF, visceral AT, and LF with glucose tolerance/insulin levels in asymptomatic and apparently healthy individuals. CRF was measured in 135 women and 177 men with a maximal treadmill graded exercise test. Indices of plasma glucose-insulin homeostasis were derived from a 3-h oral glucose tolerance test (OGTT) performed in the morning after a 12-h fast. Visceral AT levels and LF content were measured using magnetic resonance imaging and spectroscopy. For any given CRF level, women presented significantly lower visceral AT and LF than men as well as lower homeostasis model assessment of insulin resistance (HOMA-IR) and plasma glucose-insulin levels during the OGTT compared with men. In both sexes, there were significant negative correlations between CRF and HOMA-IR as well as glucose and insulin levels measured during the OGTT. Both glucose and insulin levels during the OGTT correlated positively with visceral AT and LF. In women and men, being in the top CRF tertile was associated with low levels of visceral AT and LF. Multivariable linear regression analyses suggested that visceral AT and LF were plausible mediators of the association between CRF and indices of plasma glucose-insulin homeostasis.

Prevalence of responders for hepatic fat, adiposity and liver enzyme levels in response to a lifestyle intervention in children with overweight/obesity: EFIGRO randomized controlled trial

BACKGROUND/OBJECTIVE

Exercise and lifestyle interventions have been shown to reduce hepatic fat (HF) and adiposity in youth. However, the interindividual response in HF after a lifestyle intervention with or without exercise in children is unknown. The aim of the present study was to compare interindividual variability for HF, adiposity, gamma-glutamyl transferase (GGT), and the aspartate aminotransferase to alanine aminotransferase ratio (AST/ALT) in children with overweight/obesity participating in a 22-week lifestyle intervention with (intensive intervention) or without exercise (control intervention).

METHODS

Data from 102 children (9-12 years, 55% girls) with overweight/obesity participating in the EFIGRO randomized controlled trial were analyzed. Percentage HF (magnetic resonance imaging), weight, body and fat mass index (BMI and FMI), GGT, AST/ALT, cardiorespiratory fitness (CRF, 20 meters shuttle run test) were assessed before and after the intervention by the same trained researchers. The control intervention consisted in 11 sessions of a family-based lifestyle and psycho-educational program. The intensive intervention included the control intervention plus supervised exercise (3 sessions/week).

RESULTS

The prevalence of responders for HF (54% vs. 34%), weight (27% vs. 11%), BMI (71% vs. 47%), FMI (90% vs. 60%), and GGT (69% vs. 39%) was higher in the intensive than in the control group (Ps < 0.05). Responders for weight (16 ± 3 vs. 6 ± 2 laps) and BMI (11 ± 2 vs. 3 ± 4 laps) improved more CRF levels than non-responders (Ps < 0.05).

CONCLUSIONS

The addition of exercise to a lifestyle intervention may increase the responder rates for HF, adiposity, and GGT in children with overweight/obesity. Improvements in CRF may explain differences between weight and BMI responders and non-responders.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02258126.

From syndrome X to cardiometabolic risk: clinical and public health implications

Although the first description of a syndrome defined by the co-existence of atherogenic and diabetogenic metabolic abnormalities is debated in the literature, it was Gerald Reaven who proposed, in his landmark 1988 Banting award lecture, that a significant proportion of individuals (with diabetes or not) were characterised by insulin resistance causing prejudice to cardiovascular health. However, Reaven was influenced by seminal observations made more than 50 years earlier by Himsworth who proposed that there were two forms of diabetes (insulin resistant v. insulin sensitive). Reaven went further in proposing the theory that insulin resistance was the most prevalent cause of CVD associated with metabolic abnormalities that he named syndrome X. Because there was a syndrome X documented in cardiology, the term evolved to insulin resistance syndrome. As Reaven could also find insulin-resistant individuals in non-obese subjects, he did not include obesity as a feature of syndrome X. Imaging studies then revealed that excess adipose tissue in the abdominal cavity, a condition described as visceral obesity, was the form of overweight/obesity associated with insulin resistance and its related abnormalities. As obesity risk assessment and management remain largely based on body weight (BMI) and weight loss, it is proposed that our clinical approaches and public health messages should be revisited. First, patients should be educated about the importance of monitoring their waistline as a crude index of abdominal adiposity. Secondly, public health approaches focussing on 'lifestyle vital signs' including achieving healthy waistlines rather than healthy body weights should be developed.

Associations between the rate, amount, and composition of weight loss as predictors of spontaneous weight regain in adults achieving clinically significant weight loss: A systematic review and meta-regression

Weight regain following weight loss is common although little is known regarding the associations between amount, rate, and composition of weight loss and weight regain. Forty-three studies (52 groups; n = 2379) with longitudinal body composition measurements were identified in which weight loss (≥5%) and subsequent weight regain (≥2%) occurred. Data were synthesized for changes in weight and body composition. Meta-regression models were used to investigate associations between amount, rate, and composition of weight loss and weight regain. Individuals lost 10.9% of their body weight over 13 weeks composed of 19.6% fat-free mass, followed by a regain of 5.4% body weight over 44 weeks composed of 21.6% fat-free mass. Associations between the amount (P < 0.001) and rate (P = 0.049) of weight loss and their interaction (P = 0.042) with weight regain were observed. Fat-free mass (P = 0.017) and fat mass (P < 0.001) loss both predicted weight regain although the effect of fat-free mass was attenuated following adjustment. The amount (P < 0.001), but not the rate of weight loss (P = 0.150), was associated with fat-free mass loss. The amount and rate of weight loss were significant and interacting factors associated with weight regain. Loss of fat-free mass and fat mass explained greater variance in weight regain than weight loss alone.

Impact of Intensive Lifestyle Modification on Levels of Adipokines and Inflammatory Biomarkers in Metabolically Healthy Obese Women

Background

For the metabolically healthy obese (MHO) subjects, it is unclear whether weight loss provides cardiometabolic benefits. Our objective was to evaluate whether changes in adipokine and inflammatory biomarker levels were related to lifestyle modification (with Mediterranean diet and physical exercise program).

Methods

115 women (35-55 years) with BMI of 30-40 kg/m² and ≤1 metabolic syndrome criteria were included. After a 2-year intervention, participants were classified by percent weight loss: Group 1, <5%; Group 2, ≥5%-<10%; and Group 3, ≥10%. Anthropometric data, inflammatory biomarker (IL-6, TNFa, and hsCRP) and adipokine levels (adiponectin and resistin), and lifestyle program adherence at baseline and 2 years were analyzed.

Results

The final sample comprised 67 women. 23 (38.3%) lost <5%, 22 (36.7%) lost ≥5%-<10%, and 22 (36.7%) lost ≥10% of baseline weight. After 2 years, in Group 1, adiponectin, hsCRP, IL-6, and TNFa decreased (-1.2 ng/ml, p = 0.003; -2.1 mg/l, p = 0.003; -2.4 pg/ml, p < 0.001; and -2.4 pg/ml, p = 0.001, respectively) and resistin increased (+2.4 ng/ml, p < 0.001). In Group 2, hsCRP and IL-6 decreased (-2.0 mg/l, p = 0.009 and -2.6 pg/ml, p = 0.001) but TNFa increased (+0.2 pg/ml, p = 0.02). In Group 3, resistin increased (+3.5 ng/ml, p < 0.001) but hsCRP, IL-6, and TNFa decreased (-2.0 mg/l, p = 0.009; -2.5 pg/ml, p < 0.001; and -4.1 pg/ml, p < 0.001). Adiponectin, hsCRP, and physical exercise correlated significantly to subjects' dietary adherence.

Conclusion

Weight loss reduces inflammatory biomarkers in the MHO but induces a deterioration in the adipokine profile, which does not improve with diet and exercise intervention. These findings allow us to clarify mechanisms behind inflammation and metabolic disorder genesis so as to prevent development of obesity-associated comorbidities.

Cardiovascular and Metabolic Heterogeneity of Obesity: Clinical Challenges and Implications for Management

The prevalence of obesity has increased globally over the last 2 decades. Although the body mass index has been a convenient and simple index of obesity at the population level, studies have shown that obesity defined by body mass index alone is a remarkably heterogeneous condition with varying cardiovascular and metabolic manifestations across individuals. Adipose tissue is an exquisitely active metabolic organ engaged in cross-talk between various systems; perturbation of adipose tissue results in a pathological response to positive caloric balance in susceptible individuals that directly and indirectly contributes to cardiovascular and metabolic disease. Inadequate subcutaneous adipose tissue expansion in the face of dietary triglycerides leads to visceral and ectopic fat deposition, inflammatory/adipokine dysregulation, and insulin resistance. Conversely, preferential fat storage in the lower body depot may act as a metabolic buffer and protect other tissues from lipotoxicity caused by lipid overflow and ectopic fat. Translational, epidemiological, and clinical studies over the past 30 years have clearly demonstrated a strong link between visceral and ectopic fat and the development of a clinical syndrome characterized by atherogenic dyslipidemia, hyperinsulinemia/glucose intolerance, hypertension, atherosclerosis, and adverse cardiac remodeling/heart failure. This relationship is even more nuanced when clinical entities such as metabolically healthy obesity phenotype and the obesity paradox are considered. Although it is clear that the accumulation of visceral/ectopic fat is a major contributor to cardiovascular and metabolic risk above and beyond the body mass index, implementation of fat distribution assessment into clinical practice remains a challenge. Anthropometric indexes of obesity are easily implemented, but newer imaging-based methods offer improved sensitivity and specificity for measuring specific depots. Lifestyle, pharmacological, and surgical interventions allow a multidisciplinary approach to overweight/obesity that may improve outcomes and align with a public health message to combat the growing epidemic of obesity worldwide and to build healthier lives free of cardiovascular diseases.

Association of Adipokines with Development and Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease affecting 30% of the general population and 40% to 70% of obese individuals. Adipose tissue plays a crucial role in its pathogenesis, as it produces and secretes pro- and anti-inflammatory cytokines called adipokines. Adiponectin and leptin have well-determined actions in terms of NAFLD pathophysiology. Adiponectin deficiency is associated with a pro-inflammatory condition, as it is observed in obesity and other metabolic disorders. On the other hand, increased leptin levels, above the normal levels, act as a pro-inflammatory stimulus. Regarding other adipokines (resistin, visfatin, chemerin, retinol-binding protein 4, irisin), data about their contribution to NAFLD pathogenesis and progression are inconclusive. In addition, pharmacological agents like thiazolidinediones (pioglitazone and rosiglitazone), that are used in the management of NAFLD exert favourable effects on adipokine levels, which in turn may contribute to the improvement of liver function. This review summarizes the current knowledge and developments in the association between adipokines and NAFLD and discusses possible therapeutic implications targeting the modulation of adipokine levels as a potential tool for the treatment of NAFLD.

Dose-response effects of exercise on insulin among colon cancer survivors

Physical activity is associated with a lower risk of disease recurrence among colon cancer survivors. The pathways through which physical activity may alter disease outcomes are unknown, but may include changes in metabolic growth factors, such as insulin. Between January 2015 and August 2015, 39 stage I-III colon cancer survivors were randomized to one of the three groups: usual care control, 150 min/week of aerobic exercise (low-dose) and 300 min/week of aerobic exercise (high-dose) for six months. The pre-specified key metabolic growth factor outcome was fasting insulin. Insulin resistance was quantified using the homeostatic model assessment. Mean age was 56.5 ± 10.0 years, 51% had stage III disease, 72% were treated with chemotherapy and the mean time since finishing treatment was 10.9 ± 6.1 months. Over six months, the low-dose group completed 141.5 ± 9.9 min/week of aerobic exercise, and the high-dose group completed 247.2 ± 10.7 min/week of aerobic exercise. Fasting insulin concentrations decreased 7.4 ± 9.4 pmol/L in the control group, 28.0 ± 8.3 pmol/L in the low-dose group and 20.7 ± 9.3 pmol/L in the high-dose group (nonlinear Ptrend = 0.042). Insulin resistance decreased 0.11 ± 0.20 in the control group, 0.63 ± 0.17 in the low-dose group and 0.43 ± 0.19 in the high-dose group (nonlinear Ptrend = 0.012). Aerobic exercise reduces insulin concentrations and insulin resistance among patients with stage I-III colon cancer. Prescribing 150 min/week of aerobic exercise may be sufficient for reducing insulin concentrations and insulin resistance, which may partially mediate the relationship between physical activity and colon cancer prognosis.

Liver Enzymes and the Development of Posttransplantation Diabetes Mellitus in Renal Transplant Recipients

BACKGROUND

Posttransplantation diabetes mellitus (PTDM) is common in renal transplant recipients (RTR), increasing the risk of graft failure, cardiovascular disease, and mortality. Early detection of a high risk for PTDM is warranted. Because liver function and liver fat are involved, we investigated whether serum liver markers are associated with future PTDM in RTR.

METHODS

Between 2001 and 2003, 606 RTR with a functioning allograft beyond the first year after transplantation were included of which 500 participants (56% men; age, 50 ± 12 years) were free of diabetes at baseline and had liver enzyme values (1 missing) available. Serum concentrations of alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase were measured at baseline at 6.0 (6.2-11.5) years posttransplantation. PTDM cases were recorded until April 2012.

RESULTS

During median follow-up for 9.6 years (interquartile range [IQR], 6.2-10.2) beyond baseline, 76 (15.2%) patients developed PTDM. Comparing the highest to the lower tertiles, higher liver enzyme activities were significantly related to incident PTDM for ALT (hazard ratio [HR], 2.22; IQR, 1.42-3.48), for GGT (HR, 2.93; IQR, 1.87-4.61), and for alkaline phosphatase (HR, 1.78; IQR, 1.13-2.80). The associations of ALT and GGT with development of PTDM were independent of potential confounders and risk factors, including age, sex, renal function, medication use, lifestyle factors, adiposity, presence of the metabolic syndrome, fasting glucose, HbA1c, proinsulin, and cytomegalovirus status.

CONCLUSIONS

Markers for liver function and liver fat in the subclinical range are potential markers for future PTDM, independent of other known risk factors. This may allow for early detection and management of PTDM development.

Adiponectin, lipids and atherosclerosis

PURPOSE OF REVIEW

Adiponectin is an adipokine with anti-inflammatory, antioxidant, antiatherogenic, pro-angiogenic, vasoprotective and insulin-sensitizing properties. Several factors may influence adiponectin levels, such as genetic polymorphisms, obesity / body fat distribution, diet and exercise as well as cardiovascular risk factors such as sleep deprivation and smoking as well as medications. Adiponectin has been proposed as a potential prognostic biomarker and a therapeutic target in patients with cardiometabolic diseases.

RECENT FINDINGS

This narrative review discusses the associations of adiponectin with obesity-related metabolic disorders (metabolic syndrome, nonalcoholic fatty liver disease, hyperuricaemia and type 2 diabetes mellitus). We also focus on the links between adiponectin and lipid disorders and with coronary heart disease and noncardiac vascular diseases (i.e. stroke, peripheral artery disease, carotid artery disease, atherosclerotic renal artery stenosis, abdominal aortic aneurysms and chronic kidney disease). Further, the effects of lifestyle interventions and drug therapy on adiponectin levels are briefly reviewed.

SUMMARY

Based on available data, adiponectin represents a multifaceted biomarker that may beneficially affect atherosclerosis, inflammation and insulin resistance pathways. However, there are conflicting results with regard to the associations between adiponectin levels and the prevalence and outcomes of cardiometabolic diseases. Further research on the potential clinical implications of adiponectin in the diagnosis and treatment of such diseases is needed.