Non-invasive methods for iron overload evaluation in dysmetabolic patients

IntroductionAlthough hyperferritinemia may reflect the inflammatory status of patients with non-alcoholic fatty liver disease (NAFLD), approximately 33% of hyperferritinemia cases reflect real hepatic iron overload.AimTo evaluate a non-invasive method for assessing mild iron overload in patients with NAFLD using 3T magnetic resonance imaging (MRI) relaxometry, serum hepcidin, and the expression of ferritin subunits.MethodsThis cross-sectional study assessed patients with biopsy-proven NAFLD. MRI relaxometry was performed using a 3T scanner in all patients, and the results were compared with iron content determined by liver biopsy. Ferritin, hepcidin, and ferritin subunits were assessed and classified according to ferritin levels and to siderosis identified by liver biopsy.ResultsA total of 67 patients with NAFLD were included in the study. MRI revealed mild iron overload in all patients (sensitivity, 73.5%; specificity, 70%). For mild (grade 1) siderosis, the transverse relaxation rate (R₂*) threshold was 58.9 s^?1 and the mean value was 72.5 s^?1 (SD, 33.9), while for grades 2/3 it was 88.2 s^?1 (SD, 31.9) (p < 0.001). The hepcidin threshold for siderosis was > 30.2 ng/mL (sensitivity, 87%; specificity, 82%). Ferritin H and ferritin L subunits were expressed similarly in patients with NAFLD, regardless of siderosis. There were no significant differences in laboratory test results between the groups, including glucose parameters and liver function tests.ConclusionsMRI relaxometry and serum hepcidin accurately assessed mild iron overload in patients with dysmetabolic iron overload syndrome.     

Visceral obesity and incident cancer and cardiovascular disease: An integrative review of the epidemiological evidence

Evidence shows a strong relationship between obesity, cancer and cardiovascular disease (CVD) risk. However, there is not enough evidence of the role of visceral obesity on both CVD and cancer. Visceral obesity may be more pro‐oncogenic than total body fat. Therefore, it is important to know whether abdominal obesity can lead to both CVD and cancer. The present integrative review aimed at evaluating epidemiological evidence on the potential connection of visceral obesity in the occurrence of cancer and CVD. The following databases were searched: SCOPUS, PubMed, Science Direct, Lilacs, SciELO, Google Scholar, Web of Science, Scopus and ProQuest. The presence of visceral obesity can increase the risk of some specific cancer types, but there is controversial evidence about CVD risk based on sex‐specific and ageing analyses. There is enough evidence that visceral obesity increases the risk of colorectal, pancreatic and gastro‐oesophageal cancer. However, for some types of cancer such as breast, endometrial and renal, visceral obesity is a risk only in post‐menopausal women. Regarding prostate cancer, the evidence is controversial. Despite the risk of visceral obesity being consistently associated with CVD in adults, this association disappears in sex‐specific and older adults analyses. Moreover, in older adults, the results are controversial due to the use of different measures such as waist circumference and visceral adipose tissue. However, the evidence showing visceral obesity as a risk factor to CVD remains controversial. Sex differences, ageing and body mass index (BMI) category can potentially modify this association. Therefore, further epidemiological studies with analyses stratified by sex and samples including older adults aged 65 and older are needed.     

Dietary weight loss in insulin-resistant non-obese humans: Metabolic benefits and relationship to adipose cell size

Background and Aims

Overweight and obesity increase risk for diabetes and cardiovascular disease, largely through development of insulin resistance. Benefits of dietary weight loss are documented for obese individuals with insulin resistance. Similar benefits have not been shown in overweight individuals. We sought to quantify whether dietary weight loss improves metabolic risk profile in overweight insulin-resistant individuals, and evaluated potential mediators between weight loss and metabolic response.

Gender-specific associations of body mass index and waist circumference with type 2 diabetes mellitus in Chinese rural adults: The Henan Rural Cohort Study

Aim

To assess the relationship between various obesity categories according to body mass index (BMI) and waist circumference (WC) and risk of type 2 diabetes mellitus (T2DM) among Chinese rural adults.

Relationship of low muscle mass and obesity with physical function in community dwelling older adults: Results from the Nagahama study

AimRelationships of low muscle mass and obesity with physical function were investigated in older adults.MethodsThe participants were 1922 community dwelling persons aged 60 years or older (67.7 ± 5.2 years old, 643 men and 1279 women). One-leg standing time, knee extensor muscle strength, and maximum walking speed were assessed. Muscle mass was evaluated using the bioelectrical impedance analysis (BIA) method, and skeletal mass index (SMI) was determined. For the obesity index, waist circumference with a stronger association with visceral fat was used. Participants were classified into the following four groups based on standard values of waist circumference and SMI: non-obese low-SMI, obese low-SMI, non-obese normal-SMI, and obese normal-SMI.ResultsBy two-way analysis of variance (obesity × SMI), the main effects of waist circumference and muscle mass were noted in the one-leg standing time. The maximum walking speed was higher in the non-obese than the obese group, and in the normal than the low SMI group. In the muscle strength, a main effect was noted only in the muscle mass of women. An interaction was noted in men and significant differences were detected between all combinations except between the non-obese low SMI and obese low SMI groups.ConclusionLow muscle mass and obesity negatively influence balance and walking abilities. However, the influence of low muscle mass and obesity on muscle strength were different between the sexes. In men, the relationship between obesity and muscle strength would be different depending on whether muscle mass is retained.     

Inflammatory status modulates plasma lipid and inflammatory marker responses to kiwifruit consumption in hypercholesterolaemic men

Background and aimsKiwifruit has the potential to improve markers of metabolic dysfunction, but the response may be influenced by inflammatory state. We aimed to investigate whether inflammatory state would modulate the effect of consuming two green kiwifruit daily on plasma lipids and markers of inflammation.Methods and resultsEighty-five hypercholesterolaemic men completed a 4-week healthy diet run-in, before randomisation to a controlled cross-over study of two 4-week interventions of two green kiwifruit/day plus healthy diet (intervention) or healthy diet alone (control). Anthropometric measures and fasting blood samples (plasma lipids, serum apolipoproteins A1 and B, high-sensitivity C-reactive protein (hs-CRP) and interleukin (IL)-6, tumour necrosis factor-alpha (TNF-α) and IL-10) were taken at baseline, 4 and 8 weeks. Subjects were divided into low and medium inflammatory groups, using pre-intervention hs-CRP concentrations (hs-CRP <1 and 1–3 mg/L, respectively).In the medium inflammatory group the kiwifruit intervention resulted in significant improvements in plasma high-density lipoprotein cholesterol (HDL-C) (mean difference 0.08 [95% CI: 0.03, 0.12] mmol/L [P < 0.001]), total cholesterol (TC)/HDL-C ratio (−0.29 [−0.45, −0.14] mmol/L [P = 0.001]), plasma hs-CRP (−22.1 [−33.6, −4.97]% [P = 0.01]) and IL-6 (−43.7 [−63.0, −14.1]% [P = 0.01]) compared to control treatment. No effects were seen in the low inflammatory group. There were significant between inflammation group differences for TC/HDL-C (P = 0.02), triglyceride (TG)/HDL-C (P = 0.05), and plasma IL-6 (P = 0.04).ConclusionsInflammatory state modulated responses to the kiwifruit intervention by improving inflammatory markers and lipid profiles in subjects with modestly elevated CRP, suggesting this group may particularly benefit from the regular consumption of green kiwifruit.Registered 16th March 2010, Australian New Zealand Clinical Trials Registry (no. ACTRN12610000213044), www.ANZCTR.org.au.     

Evaluation of waist-to-height ratio to predict 5 year cardiometabolic risk in sub-Saharan African adults

Background and aimsSimple, low-cost central obesity measures may help identify individuals with increased cardiometabolic disease risk, although it is unclear which measures perform best in African adults. We aimed to: 1) cross-sectionally compare the accuracy of existing waist-to-height ratio (WHtR) and waist circumference (WC) thresholds to identify individuals with hypertension, pre-diabetes, or dyslipidaemia; 2) identify optimal WC and WHtR thresholds to detect CVD risk in this African population; and 3) assess which measure best predicts 5-year CVD risk.Methods and resultsBlack South Africans (577 men, 942 women, aged >30years) were recruited by random household selection from four North West Province communities. Demographic and anthropometric measures were taken. Recommended diagnostic thresholds (WC > 80 cm for women, >94 cm for men; WHtR > 0.5) were evaluated to predict blood pressure, fasting blood glucose, lipids, and glycated haemoglobin measured at baseline and 5 year follow up. Women were significantly more overweight than men at baseline (mean body mass index (BMI) women 27.3 ± 7.4 kg/m², men 20.9 ± 4.3 kg/m²); median WC women 81.9 cm (interquartile range 61–103), men 74.7 cm (63–87 cm), all P < 0.001). In women, both WC and WHtR significantly predicted all cardiometabolic risk factors after 5 years. In men, even after adjusting WC threshold based on ROC analysis, WHtR better predicted overall 5-year risk. Neither measure predicted hypertension in men.ConclusionsThe WHtR threshold of >0.5 appears to be more consistently supported and may provide a better predictor of future cardiometabolic risk in sub-Saharan Africa.     

An examination of sex and racial/ethnic differences in the metabolic syndrome among adults: A confirmatory factor analysis and a resulting continuous severity score

Objective

The metabolic syndrome (MetS) is typically diagnosed based on abnormalities in specific clustered clinical measures that are associated with increased risk for coronary heart disease (CHD) and Type 2 diabetes mellitus (T2DM). However, current MetS criteria result in racial/ethnic discrepancies. Our goals were to use confirmatory factor analysis (CFA) to delineate differential contributions to MetS by sub-group, and if contributions were discovered, develop sex and racial/ethnic-specific equations to calculate MetS severity.

Research Design and Methods

Using data on adults from the National Health and Nutrition Examination Survey 1999–2010, we performed a CFA of a single MetS factor that allowed differential loadings across groups, resulting in a sex and race/ethnicity-specific continuous MetS severity score.

Results

Loadings to the single MetS factor differed by sub-group for each MetS component (p < 0.001), with lower factor loadings among non-Hispanic-blacks for triglycerides and among Hispanics for waist circumference. Systolic blood pressure exhibited low factor loadings among all groups. MetS severity scores were correlated with biomarkers of future disease (high-sensitivity C-reactive-protein, uric acid, insulin resistance). Non-Hispanic-black-males with diabetics had a low prevalence of MetS but high MetS severity scores that were not significantly different from other racial/ethnic groups.

Conclusions

This analysis among adults uniquely demonstrated differences between sexes and racial/ethnic groups regarding contributions of traditional MetS components to an assumed single factor. The resulting equations provide a clinically-accessible and interpretable continuous measure of MetS for potential use in identifying adults at higher risk for MetS-related diseases and following changes within individuals over time. These equations hold potential to be a powerful new outcome for use in MetS-focused research and interventions.