Elevated serum tartrate-resistant acid phosphatase isoform 5a levels in metabolic syndrome

Biomarker profiles in obesity patients and their relation to cardiac dysfunction

Aim: Current knowledge on the role of obesity in causing cardiac dysfunction is insufficient. Several biomarkers reflecting biological processes that may play a role in the occurrence of cardiac dysfunction in obesity patients are available. Purpose: To compare cardiovascular biomarker profiles between obesity patients and nonobese controls, and between obesity patients with and without cardiac dysfunction, in order to better understand the underlying pathophysiology of cardiac dysfunction in obesity patients. Materials & methods: Blood samples were obtained from 100 obesity patients (BMI ≥35 kg/m²) without known cardiovascular disease, and from 50 age- and gender-matched nonobese controls (BMI ≤30 kg/m²). The third cardiovascular panel of the Olink Multiplex platform was used for the measurement of 92 biomarkers. Results: The majority (53%) of biomarkers were elevated in obesity patients compared with nonobese controls. Only 5% of the biomarkers were elevated in obesity patients with cardiac dysfunction compared with those without. Biomarkers discriminating cardiac dysfunction from no cardiac dysfunction in obesity patients differed from those discriminating obese from nonobese patients. An elastic net model for the prediction of cardiac dysfunction in obesity patients had a high area under the receiver operating curve of 0.87 (95% CI: 0.79-0.94; p < 0.001). The sensitivity of this model was 84% and the specificity was 79%. Conclusion: A multiplex immunoassay was used for the first time in obesity patients without known cardiovascular disease. These patients have cardiovascular biomarker profiles that are clearly different from nonobese controls. Comparison of obesity patients with and without cardiac dysfunction suggested an important role for inflammation, atherosclerosis and insulin resistance in the underlying pathophysiology of cardiac dysfunction in obesity patients.

Intensive weight gain therapy in patients with anorexia nervosa results in improved serum tartrate-resistant acid phosphatase (TRAP) 5a and 5b isoform protein levels

AIM

Tartrate-resistant acid phosphatase (TRAP) exists as isoforms 5a and 5b. TRAP 5a is a biomarker of chronic inflammation and influences adipose tissue and 5b associates with bone metabolism/pathologies. The aim was to investigate the association of serum TRAP 5a/5b isoforms with fat and bone markers and anthropometric parameters in patients with anorexia nervosa (AN) during weight gain therapy.

METHODS

Twenty-five Swedish female AN patients, age 16-24 years, were treated for 12 weeks with a high-energy diet with six meals daily. Serum TRAP 5a/5b, markers of fat/glucose metabolism, markers of bone resorption and formation were measured. Parameters of bone and body composition were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography.

RESULTS

BMI increased from median 15.4 kg/m² to 19.0 kg/m², p < 0.0001. TRAP 5a and 5a/5b ratio increased but TRAP 5b decreased during the study. TRAP Δ5a and Δ5b correlated with Δinsulin and Δadiponectin, respectively. TRAP 5b correlated with trabecular density at start but not at week 12. At 12 weeks, TRAP 5b correlated with CTX, and Δ decrease in TRAP 5b correlated to Δ increase in bone-specific alkaline phosphatase.

CONCLUSIONS

This clinical interventional study resulted in increased BMI in patients with AN. The decreased TRAP 5b protein levels confirm a role for TRAP 5b as a marker of bone resorption, whereas increased TRAP 5a seemed to derive from systemic changes in bone as well as metabolic changes. The combined detection of TRAP 5a and TRAP 5b in serum could be an indicator of improved bone metabolism.

LEVEL OF EVIDENCE

Level III, prospective interventional cohort study.

Bone health in diabetes and prediabetes

Bone fragility has been recognized as a complication of diabetes, both type 1 diabetes (T1D) and type 2 diabetes (T2D), whereas the relationship between prediabetes and fracture risk is less clear. Fractures can deeply impact a diabetic patient's quality of life. However, the mechanisms underlying bone fragility in diabetes are complex and have not been fully elucidated. Patients with T1D generally exhibit low bone mineral density (BMD), although the relatively small reduction in BMD does not entirely explain the increase in fracture risk. On the contrary, patients with T2D or prediabetes have normal or even higher BMD as compared with healthy subjects. These observations suggest that factors other than bone mass may influence fracture risk. Some of these factors have been identified, including disease duration, poor glycemic control, presence of diabetes complications, and certain antidiabetic drugs. Nevertheless, currently available tools for the prediction of risk inadequately capture diabetic patients at increased risk of fracture. Aim of this review is to provide a comprehensive overview of bone health and the mechanisms responsible for increased susceptibility to fracture across the spectrum of glycemic status, spanning from insulin resistance to overt forms of diabetes. The management of bone fragility in diabetic patient is also discussed.

抗酒石酸酸性磷酸酶在恶性肿瘤中的研究进展

抗酒石酸酸性磷酸酶(type 5 acid phosphatase/tartrate-resistant acid phosphatase, ACP5/TRACP/TRAP)是酸性磷酸酶家族中的金属蛋白酶, 是骨吸收和破骨细胞活性的良好标志物. 近来发现ACP5在多种肿瘤中的表达比配对正常组织中的表达显著上调, 该现象提示, ACP5可能肿瘤的发生发展中起到一定的作用.