A Reliability Study in a Cohort of 207 Apparently Healthy Participants

The reliability of single time point measurements of the novel adipokines retinol-binding protein 4 and omentin-1 in the blood has not been evaluated in large samples yet. The present study aimed to assess the amount of biological variation of these two adipokines within individuals. The study sample comprised 207 participants (124 women and 83 men) from Potsdam (Germany) and surrounding areas, with an average age of 56.5 years (SD 4.2). Blood samples were collected from each participant twice, approximately four months apart. Using enzyme linked immunosorbent assays, the concentrations of retinol- binding protein 4 and omentin-1 were determined in EDTA plasma. As indicators of reliability, intraclass correlation coefficients (ICCs) were calculated from the repeated biomarker measurements. The ICCs for repeated retinol- binding protein 4 and omentin-1 measurements were 0.77 (95% CI 0.71, 0.82) and 0.83 (95% CI 0.78, 0.87), respectively, indicating for both adipokines excellent reliability. ICCs were stable across strata according to sex, age, BMI, and blood pressure. Thus, for epidemiological studies it seems reasonable to rely on concentrations of retinol-binding protein 4 and omentin-1 in samples from a single time point if repeated measurements are not available

Relationship of Retinol Binding Protein Four Serum Level on Endometrial Hyperplasia and Endometrial Carcinoma

Abstract Objective : To determine the relationship of elevated serum retinol binding protein 4 with abnormal uterine bleeding Methods : This study was an observational quantitative with cross sectional methods, with all women who had abnormal uterine bleeding caused either by endometrial carcinoma or endometrial hyperplasia at RSUP Prof.DR.RD Kandou, and affiliation hospitals from November 2016 until April 2017. Data were analyzed With SPSS version 2.0 to see the significancy level. Results: Of 26 research subjects, 23 subjects with endomtrial hyperplasia and 3 subjects with endometrial carcinoma. From the total of 26 malignancy and hyperplasia diagnoses, 21 had IMT> 25 and 23 were diagnosed with Endometrial Hyperplasia and 3 Carcinoma Endometrium. 18 subjects had elevated serum RBP4 levels, with 15 people with endometrial hyperplasia and 3 with endometrial carcinoma. With the Fischer Exact test statistic, serum retinol binding protein 4 levels were found in both endometrial hyperplasia and endometrial carcinoma p = 1.00, meaning no significant difference for the occurrence of abnormal uterine bleeding. Conclusion: There was no significant association between serum retinol binding protein 4 between endomterium carcinoma and endometrial hyperplasia. Keywords: abnormal uterine bleeding, endometrial carcinoma, endometrial hyperplasia, serum retinol binding protein 4   Abstrak Tujuan : Mengetahui adanya hubungan peningkatan kadar serum retinol binding protein 4 pada hyperplasia endomterium dengan carcinoma endometrium Metode : Penelitian ini adalah jenis kuantitatif observasional secara potong lintang, dengan semua perempuan yang mengalami perdarahan uterus abnormal yang disebabkan oleh hiperplasia endometrium atau carcinoma endometrium di Bagian Kebidanan dan Kandungan Rumah Sakit Umum Pusat (RSUP) Prof.DR.R.D Kandou, dan RS jejaring mulai November 2016 sampai April 2017.Data dianalisa dengan SPSS versi 2.0 untuk melihat tingkat kemaknaannya. Hasil : Dari 26 subjek penelitian, 23 subjek dengan hyperplasia endomtrium dan 3 subjek dengan carcinoma endometrium. Didapatkan data penelitian dari total keganasan diagnosa  dan hiperplasia sejumlah 26 orang, sebanyak 21 orang memiliki IM T>25 dan sebanyak 23 orang didiagnosa dengan Hiperplasia Endometrium dan 3 orang karsinoma Endometrium. Didapatkan sebanyak 18 subyek penelitian mengalami peningkatan kadar serum RBP 4, dengan 15 orang yang mengalami hiperplasia endometrium dan 3 orang dengan karsinoma endometrium. Dengan uji statistik Fischer Exact test, didapatkan kadar serum retinol binding protein 4 baik pada hiperplasia endometrium dengan karsinoma endometrium p=1.00, mengartikan tidak mempunyai perbedaan bermakna untuk terjadinya perdarahan uterus abnormal. Kesimpulan : Tidak terdapat hubungan bermakna kadar serum retinol binding protein 4 antara karsinoma endomterium dengan hiperplasia endometrium. Kata kunci : hiperplasia endometrium , kadar serum retinol binding protein 4, karsinoma endometrium, perdarahan uterus abnorma

RPB4 and pathogenesis of diabetes

Obesity is an important risk factor for a number of chronic diseases that impose a huge burden on individuals and society. Recently it has become clear that adipose tissue-secreted products may play a significant role in mediating many obesity-related diseases including diabetes. Thus, in addition to being an energy depot, the adipocyte is a highly active cell, secreting a plethora of factors with profound effects on a number of organs and systems. The study of these factors and their endocrine effects has become a rapidly evolving and dynamic area of endocrinology. One paradigm for explaining the deleterious effects of adipokines is related to the sheer increase in adipose tissue mass in obesity. When preadipocytes differentiate to become mature adipocytes, they acquire the ability to synthesize numerous proteins, including cytokines, growth factors, and hormones that are involved in overall energy homeostasis and various paracrine effects. In health, these proteins do not spill over significantly into the circulation. In obesity, the massive increase in fat mass leads to a significant increase in circulation of many adipose tissue secreted factors that may have pathogenic effects. For example, the increase in circulating angiotensin II in obesity is related at least in part due to excess adiposity and may mediate hypertension (1). In recent years, adipose tissue has been found to be a major source of many proteins that may directly contribute to vascular injury, diabetes, and atherogenesis (2). These proinflammatory adipokines include TNF-α, IL-6, leptin, plasminogen activator inhibitor-1, angiotensinogen, and resistin, among many others. In contrast, the adipokine adiponectin confers protection against inflammation, atherogenesis, and obesity-linked insulin resistance

Serum retinol-binding protein 4 levels in polycystic ovary syndrome

OBJECTIVE: Serum levels of retinol-binding protein 4 (RBP4), an adipokine thought to affect systemic insulin sensitivity, were compared between women with polycystic ovary syndrome (PCOS) and non-PCOS controls to evaluate the association of RBP4 with clinical, hormonal and metabolic parameters of PCOS. SUBJECTS AND METHODS: Serum RBP4 levels were analysed in 278 women with PCOS (age range 18-57 years) and 191 non-PCOS controls (age 20-53 years) by enzyme-linked immunosorbent assay. RESULTS: Serum levels of RBP4 were increased in women with PCOS compared with control women in the whole population (45.1 ± 24.0 (s.d.) vs 33.5 ± 18.3 mg/L, P <0.001). Age-stratified analysis showed that serum RBP4 levels were increased in women with PCOS aged ≤30 years compared with controls (47.7 ± 23.5 vs 27.1 ± 10.4 mg/L, P <0.001), whereas no significant differences were seen in the other age groups. No significant correlations of RBP4 were seen with either steroids or indices of insulin resistance. CONCLUSIONS: Although serum RBP4 levels were increased in younger women with PCOS compared with age-matched non-PCOS controls, RBP4 does not seem to be a good marker of insulin resistance or other metabolic derangements in women with PCOS.Peer reviewe

Serum levels of RBP4 and adipose tissue levels of PTP1B are increased in obese men resident in northeast Scotland without associated changes in ER stress response genes

Peer reviewedPublisher PD

Retinol-Binding Protein-4 in Women With Untreated Essential Hypertension

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Prospective Relation of Circulating Adipokines to Incident Metabolic Syndrome: The Framingham Heart Study

BACKGROUND: Adipokines are elaborated by adipose tissue and are associated with glycemic, lipid, and vascular traits. We hypothesized that in a cross-sectional analysis circulating adipokines are altered among subsets of obesity stratified by presence versus absence of metabolic syndrome (MetS) and prospectively predict the incidence of MetS. METHODS AND RESULTS: Participants in the community-based Framingham Third Generation Cohort who attended examination cycle 1 were included in the study (2002-2005; N=3777, mean age, 40 years; 59% women). Circulating adiponectin, leptin, leptin receptor, fetuin-A, fatty acid-binding protein 4, and retinol binding protein 4 were assayed and related to incident MetS in follow-up (mean 6 years). The adipokines were compared among individuals with excess body weight (body mass index \u3e /=25 kg/m2) and prevalent MetS, excess body weight without MetS (metabolically healthy obese), and normal-weight with MetS (metabolically obese, normal-weight) with normal-weight participants without MetS as a referent. Metabolically healthy obese individuals (n=1467) had higher circulating levels of fetuin-A and fatty acid-binding protein 4 but lower levels of leptin, leptin receptor, and adiponectin (P \u3c 0.001 for all). The adipokine panel was associated with incident MetS (263 new-onset cases; P=0.002). Higher circulating concentrations of retinol-binding protein 4 and fetuin-A were associated with incidence of MetS (odds ratio per 1-SD increment log marker, 1.21; 95% CI, 1.03-1.41 [P=0.02] and 1.17; 95% CI, 1.01-1.34 [P=0.03], respectively). CONCLUSIONS: In our community-based sample of young to middle-aged adults, metabolically healthy obese individuals demonstrated an adverse adipokine profile. Higher circulating levels of retinol-binding protein 4 and fetuin-A marked future cardiometabolic risk

Retinol and Retinol Binding Protein 4 Levels and Cardiometabolic Disease Risk

Background: Despite mechanistic studies linking retinol and RBP4 (retinol binding protein 4) to the pathogenesis of cardiovascular diseases (CVD) and type 2 diabetes (T2D), epidemiological evidence is still conflicting. We investigated whether conflicting results of previous studies may be explained by differences in the association of retinol and RBP4 with cardiometabolic risk across subgroups with distinct sex, hypertension state, liver, or kidney function. Methods: We used case-cohorts nested in the EPIC (European Prospective Investigation Into Cancer and Nutrition)-Potsdam cohort (N=27 548) comprising a random sample of participants (n=2500) and all physician-verified cases of incident CVD (n=508, median follow-up time 8.2 years) and T2D (n=820, median follow-up time 6.3 years). We estimated nonlinear and linear multivariable-adjusted associations between the biomarkers and cardiometabolic diseases by restricted cubic splines and Cox regression, respectively, testing potential interactions with hypertension, liver, and kidney function. Additionally, we performed 2-sample Mendelian Randomization analyses in publicly available data. Results: The association of retinol with cardiometabolic risk was modified by hypertension state (P interaction CVDP interaction T2D&lt;0.001). Retinol was associated with lower cardiometabolic risk in participants with treated hypertension (hazard ratio(per SD) [95% CI]: CVD, 0.71 [0.56-0.90]; T2D, 0.81 [0.70-0.94]) but with higher cardiometabolic risk in normotensive participants (CVD, 1.32 [1.06-1.64]; T2D, 1.15 [0.98-1.36]). Our analyses also indicated a significant interaction between RBP4 and hypertension on CVD risk (P interaction=0.04). Regarding T2D risk, we observed a u-shaped association with RBP4 in women (P nonlinearity=0.01, P effect=0.02) and no statistically significant association in men. The biomarkers\u27 interactions with liver or kidney function were not statistically significant. Hypertension state-specific associations for retinol concentrations with cardiovascular mortality risk were replicated in National Health and Nutrition Examination Survey III. Conclusions: Our findings suggest a hypertension-dependent relationship between plasma retinol and cardiometabolic risk and complex interactions of RBP4 with sex and hypertension on cardiometabolic risk