There are conflicting data on whether variations of physiologic cortisol levels associated with cardiovascular risk. We hypothesize that prior discordant findings are related to problems associated with varying sample size, techniques for assessing cardiovascular risk and failure to adequately account for environmental factors. To address these issues, we utilized a large sample size, selected the Framingham risk score to compute cardiovascular risk and performed the study in a highly controlled setting. We had two main objectives: determine whether higher, yet physiologic, cortisol levels associated with increased cardiovascular risk and determine whether caveolin-1 (rs926198) risk allele carriers associated with increased cardiovascular risk. This was a cross-sectional study of 574 non-diabetic individuals who completed a common protocol. Data collection included fasting blood samples, blood pressure measurements and a 24-h urine-free cortisol collection. Five hundred seventeen of these participants also completed caveolin-1 genotyping. Subjects were classified as belonging to either the low-mode or high-mode urine-free cortisol groups, based on the bimodal distribution of urine-free cortisol. In multivariate analysis, Framingham risk score was statistically higher in the high-mode cortisol group (10.22 (mean) ± 0.43 (s.e.m.)) compared to the low-mode cortisol group (7.73 ± 0.34), P < 0.001. Framingham risk score was also statistically higher in the caveolin-1 risk allele carriers (8.91 ± 0.37) compared to caveolin-1 non-risk allele carriers (7.59 ± 0.48), P = 0.034. Overall, the estimated effect on Framingham risk score of carrying the caveolin-1 risk allele was 1.33 ± 0.61, P = 0.029. Both urinary cortisol and caveolin-1 risk allele status are independent predictors of Framingham risk score.
Andrea V Haas, Paul N Hopkins, Nancy J Brown, Luminita H Pojoga, Jonathan S Williams, Gail K Adler, and Gordon H Williams
Shenglong Le, Leiting Xu, Moritz Schumann, Na Wu, Timo Törmäkangas, Markku Alén, Sulin Cheng, and Petri Wiklund
The directional influences between serum sex hormone-binding globulin (SHBG), adiposity and insulin resistance during pubertal growth remain unclear. The aim of this study was to investigate bidirectional associations between SHBG and insulin resistance (HOMA-IR) and adiposity from childhood to early adulthood.
Participants were 396 healthy girls measured at baseline (age 11.2 years) and at 1, 2, 4 and 7.5 years. Serum concentrations of estradiol, testosterone and SHBG were determined by ELISA, glucose and insulin by enzymatic photometry, insulin-like growth factor 1 (IGF-1) by time-resolved fluoroimmunoassays, whole-body fat mass by dual-energy X-ray absorptiometry and HOMA-IR were determined by homeostatic model assessment. The associations were examined using cross-lagged path models.
In a cross-lagged path model, SHBG predicted HOMA-IR before menarche β = −0.320 (95% CI: −0.552 to −0.089), P = 0.007, independent of adiposity and IGF-1. After menarche, no directional effect was found between SHBG and insulin resistance or adiposity.
Our results suggest that in early puberty, decline in SHBG predicts development of insulin resistance, independent of adiposity. However, after menarche, no directional influences between SHBG, adiposity and insulin resistance were found, suggesting that observational associations between SHBG, adiposity and insulin resistance in pubertal children may be subject to confounding. Further research is needed to understand the underlying mechanisms of the associations between SHBG and cardiometabolic risk markers in peripubertal children.
Ann-Kristin Picke, Graeme Campbell, Nicola Napoli, Lorenz C Hofbauer, and Martina Rauner
The prevalence of type 2 diabetes mellitus (T2DM) is increasing worldwide, especially as a result of our aging society, high caloric intake and sedentary lifestyle. Besides the well-known complications of T2DM on the cardiovascular system, the eyes, kidneys and nerves, bone strength is also impaired in diabetic patients. Patients with T2DM have a 40–70% increased risk for fractures, despite having a normal to increased bone mineral density, suggesting that other factors besides bone quantity must account for increased bone fragility. This review summarizes the current knowledge on the complex effects of T2DM on bone including effects on bone cells, bone material properties and other endocrine systems that subsequently affect bone, discusses the effects of T2DM medications on bone and concludes with a model identifying factors that may contribute to poor bone quality and increased bone fragility in T2DM.
Elena Izkhakov, Joseph Meyerovitch, Micha Barchana, Yacov Shacham, Naftali Stern, and Lital Keinan-Boker
Thyroid cancer (TC) survivors may be at risk of subsequent cardiovascular and cerebrovascular (CaV&CeV) morbidity. The 2009 American Thyroid Association (ATA) guidelines recommended less aggressive treatment for low-risk TC patients. The aim of this study was to assess the atherosclerotic CaV&CeV outcome of Israeli TC survivors compared to individuals with no thyroid disease, and the atherosclerotic CaV&CeV outcome before (2000–2008) and after (2009–2011) implementation of the 2009 ATA guidelines.
All members of the largest Israeli healthcare organization who were diagnosed with TC from 1/2000 to 12/2014 (study group) and age- and sex-matched members with no thyroid disease (controls) were included. Adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using Cox proportional hazards models.
The mean follow-up was 7.6 ± 4.2 and 7.8 ± 4.1 years for the study (n = 5,677, 79% women) and control (n = 23,962) groups, respectively. The former had an increased risk of new atherosclerotic CaV&CeV events (adjusted HR 1.26, 95% CI 1.15–1.39). The 5-year incidence of CaV&CeV was lower (adjusted HR 0.49, 95% CI 0.38–0.62) from 2009 to 2011 compared to 2000 to 2008, but remained higher in the study group than in the control group (adjusted HR 1.5, 95% CI 1.14–1.69).
This large Israeli population-based cohort study showed greater atherosclerotic CaV&CeV morbidity in TC survivors compared to individuals with no thyroid diseases. There was a trend toward a decreased 5-year incidence of atherosclerotic CaV&CeV events among TC survivors following the implementation of the 2009 ATA guidelines, but it remained higher compared to the general population.
Ananda A Santana-Ribeiro, Giulliani A Moreira-Brasileiro, Manuel H Aguiar-Oliveira, Roberto Salvatori, Vitor O Carvalho, Claudia K Alvim-Pereira, Carlos R Araújo-Daniel, Júlia G Reis-Costa, Alana L Andrade-Guimarães, Alécia A Oliveira-Santos, Edgar R Vieira, and Miburge B Gois-Junior
Walking and postural balance are extremely important to obtain food and to work. Both are critical for quality of life and ability to survive. While walking reflects musculoskeletal and cardiopulmonary systems, postural balance depends on body size, muscle tone, visual, vestibular and nervous systems. Since GH and IGF-I act on all these systems, we decided to study those parameters in a cohort of individuals with severe short stature due to untreated isolated GH deficiency (IGHD) caused by a mutation in the GHRH receptor gene. These IGHD subjects, despite reduction in muscle mass, are very active and have normal longevity.
In a cross-sectional study, we assessed walking (by a 6-min walk test), postural balance (by force platform) and fall risk (by the 'Timed Up and Go' test) in 31 IGHD and 40 matched health controls.
The percentage of the walked distance measured in relation to the predicted one was similar in groups, but higher in IGHD, when corrected by the leg length. Absolute postural balance data showed similar velocity of unipodal support in the two groups, and better values, with open and closed eyes and unipodal support, in IGHD, but these differences became non-significant when corrected for height and lower-limb length. The time in 'Timed Up and Go' test was higher in IGHD cohort, but still below the cut-off value for fall risk.
IGHD subjects exhibit satisfactory walking and postural balance, without increase in fall risk.
Xiaomin Nie, Yiting Xu, Xiaojing Ma, Yun Shen, Yufei Wang, and Yuqian Bao
A high level of free triiodothyronine (FT3) within the reference range may be a potential metabolic risk marker. However, the relationship between different fat depots and FT3 has remained unclear.
We aimed to explore the relationships between segmental fat distribution and FT3 in euthyroid middle-aged and elderly men and postmenopausal women.
A total of 891 subjects (394 men and 497 women) were enrolled. A bioelectrical impedance analyzer was used to measure total, trunk, arm and leg fat mass (FM) and fat percentage (fat%). The leg fat mass to trunk fat mass ratio (LTR) was calculated to evaluate the relative distribution of leg fat compared with that of trunk fat. Thyroid hormones were measured by electrochemical luminescence immunoassay.
FT3 in men did not change significantly with increases in LTR quartiles, while FT3 in women decreased significantly (P for trend = 0.004). In multivariate linear regression analysis, multiple metabolic and cardiovascular risk factors were adjusted. The LTR was negatively related to FT3 in women (P < 0.05). After further mutual adjustment for trunk fat and leg fat parameters, trunk FM and fat% were positively related to FT3, while leg FM and fat% were negatively related to FT3 in women (all P < 0.05).
In euthyroid postmenopausal women, trunk fat was positively correlated with FT3, whereas leg fat was negatively correlated with FT3. Our findings supported that a high level of FT3 within the reference range was related to adverse fat distribution.
Marc Blondon, Emmanuel Biver, Olivia Braillard, Marc Righini, Pierre Fontana, and Alessandro Casini
Vitamin D deficiency is associated with increased risks of arterial and venous cardiovascular events. Hypothetically, supplementation with vitamin D may lead to a less prothrombotic phenotype, as measured by global coagulation assays and fibrin clot structure.
In this prospective cohort study, we enrolled adult outpatients attending the Primary Care Division of the Geneva University Hospitals with a severe vitamin D deficiency (25-hydroxyvitamin-D3 (25-OHD) <25 nmol/L), excluding obese patients or with a recent acute medical event. We evaluated changes in coagulation times, thrombin generation assay, clot formation and clot lysis time, 25-OHD and parathormone before and 1–3 months after cholecalciferol oral supplementation with one-time 300,000 IU then 800 IU daily. Paired t-tests with a two-sided alpha of 0.05 compared absolute mean differences.
The 48 participants had a mean age of 43.8 ± 13.8 years. After supplementation, 25-OHD levels increased from 17.9 ± 4.6 nmol/L to 62.5 ± 20.7 nmol/L 6.4 ± 3.0 weeks after inclusion. Endogenous thrombin potential and thrombin generation peak values both decreased significantly (−95.4 nM × min (95%CI −127.9 to −62.8), P < 0.001; −15.1 nM (−23.3 to −6.8), P < 0.001). The maximum absorbance by turbidimetry decreased significantly (P = 0.001) after supplementation. There was no change in clot lysis time, coagulation times or plasminogen activator inhibitor-1 and homocysteine levels.
In severe vitamin D deficiency, a high-dose cholecalciferol supplementation was associated with a reduction in thrombin generation and an average decreased number of fibrin protofibrils per fibers and fibrin fiber size measured by turbidimetry. This suggests that severe vitamin D deficiency may be associated with a potentially reversible prothrombotic profile.
Kristin Godang, Karolina Lundstam, Charlotte Mollerup, Stine Lyngvi Fougner, Ylva Pernow, Jörgen Nordenström, Thord Rosén, Svante Jansson, Mikael Hellström, Jens Bollerslev, Ansgar Heck, and the SIPH Study Group
Mild primary hyperparathyroidism has been associated with increased body fat mass and unfavorable cardiovascular risk factors.
To assess the effect of parathyroidectomy on fat mass, glucose and lipid metabolism.
Design, patients, interventions, main outcome measures
119 patients previously randomized to observation (OBS; n = 58) or parathyroidectomy (PTX; n = 61) within the Scandinavian Investigation of Primary Hyperparathyroidism (SIPH) trial, an open randomized multicenter study, were included. Main outcome measures for this study were the differences in fat mass, markers for lipid and glucose metabolism between OBS and PTX 5 years after randomization.
In the OBS group, total cholesterol (Total-C) decreased from mean 5.9 (±1.1) to 5.6 (±1.0) mmol/L (P = 0.037) and LDL cholesterol (LDL-C) decreased from 3.7 (±1.0) to 3.3 (±0.9) mmol/L (P = 0.010). In the PTX group, the Total-C and LDL-C remained unchanged resulting in a significant between-group difference over time (P = 0.013 and P = 0.026, respectively). This difference was driven by patients who started with lipid-lowering medication during the study period (OBS: 5; PTX: 1). There was an increase in trunk fat mass in the OBS group, but no between-group differences over time. Mean 25(OH) vitamin D increased in the PTX group (P < 0.001), but did not change in the OBS group. No difference in parameters of glucose metabolism was detected.
In mild PHPT, the measured metabolic and cardiovascular risk factors were not modified by PTX. Observation seems safe and cardiovascular risk reduction should not be regarded as a separate indication for parathyroidectomy based on the results from this study.
Maria Angela D'amico, Barbara Ghinassi, Pascal Izzicupo, Lamberto Manzoli, and A Di Baldassarre
Chromogranin A (CgA (CHGA)) is the major soluble protein co-stored and co-released with catecholamines and can function as a pro-hormone by giving rise to several bioactive peptides. This review summarizes the physiological functions, the pathogenic implications, and the recent use of these molecules as biomarkers in several pathological conditions. A thorough literature review of the electronic healthcare databases MEDLINE, from January 1985 to September 2013, was conducted to identify articles and studies concerned with CgA and its processing. The search strategies utilized keywords such as chromogranin A, vasostatins 1 and 2, chromofungin, chromacin, pancreastatin, catestatin, WE14, chromostatin, GE25, parastatin, and serpinin and was supplemented by the screening of references from included papers and review articles. A total of 209 English-language, peer-reviewed original articles or reviews were examined. The analysis of the retrospective literature suggested that CgA and its several bioactive fragments exert a broad spectrum of regulatory activities by influencing the endocrine, the cardiovascular, and the immune systems and by affecting the glucose or calcium homeostasis. As some peptides exert similar effects, but others elicit opposite responses, the regulation of the CgA processing is critical to maintain homeostasis, whereas an unbalanced production of peptides that exert opposing effects can have a pathogenic role in several diseases. These clinical implications entail that CgA and its derived peptides are now used as diagnostic and prognostic markers or to monitor the response to pharmacological intervention not only in endocrine tumors, but also in cardiovascular, inflammatory, and neuropsychiatric diseases.
Maria Lola Evia-Viscarra, Edel Rafael Rodea-Montero, Evelia Apolinar-Jiménez, and Silvia Quintana-Vargas
The aim of this study was to estimate the prevalence of metabolic syndrome (MS) and its components in obese Mexican adolescents and to compare the clinical, anthropometric, and biochemical characteristics between patients with and without MS by sex. We conducted a cross-sectional study with a sample of 110 obese adolescents (boys and girls) from 8 to 16 years old (BMI ≥95th percentile), who were recruited in the pediatric obesity clinic of a third-level care hospital. A frequency analysis was used to estimate the prevalence of MS and its components, and the assessments were compared between the sexes and between the groups with and without MS using the Kruskal–Wallis test. The prevalence of MS was 62%. In order of prevalence, the following components of MS were observed in the sample: abdominal obesity (88%), high triglycerides (TG) (85%), low HDL-C (60%), hypertension (35%), and hyperglycemia (5%). In the groups with MS, hypertension (P<0.001), waist circumference (P=0.003), and TG (P=0.012) were significantly higher, and HDL-C (P<0.001) was significantly lower. In conclusion the prevalence of MS and its components is high among obese Mexican-Hispanic children. These findings show the importance of preventing and treating obesity in the early stages of life in order to decrease the incidence rates of cardiovascular disease and type 2 diabetes mellitus.