Serum Preptin Levels Research Articles

Elevated serum preptin levels as a marker for non-alcoholic fatty liver disease severity in type 2 diabetes mellitus patients

Elevated serum preptin levels as a marker for non-alcoholic fatty liver disease severity in type 2 diabetes mellitus patients

Preptin: A New Bone Metabolic Parameter?

Preptin is a 34-aminoacid peptide derived from the E-peptide of pro-insulin-like growth factor 2 (pro-IGF2) that is co-secreted with insulin and upregulates glucose-mediated insulin secretion. High serum preptin levels were described in conditions associated with insulin resistance, such as polycystic ovary syndrome and type 2 diabetes mellitus (T2M). Insulin and also IGF2 are known to be anabolic bone hormones. The "sweet bone" in T2M usually associates increased density, but altered microarchitecture. Therefore, preptin was proposed to be one of the energy regulatory hormones that positively impacts bone health. Experimental data demonstrate a beneficial impact of preptin upon the osteoblasts. Preptin also appears to regulate osteocalcin secretion, which in turn regulates insulin sensitivity. Preptin is greatly influenced by the glucose tolerance status and the level of physical exercise, both influencing the bone mass. Clinical studies describe low serum preptin concentrations in osteoporosis in both men and women, therefore opening the way towards considering preptin a potential bone anabolic therapy. The current review addresses the relationship between preptin and bone mass and metabolism in the experimental and clinical setting, also considering the effects of preptin on carbohydrate metabolism and the pancreatic-bone loop.

Preptin Deficiency Does Not Protect against High-Fat Diet-Induced Metabolic Dysfunction or Bone Loss in Mice.

Preptin is derived from the cleavage of the E-peptide of pro-insulin-like growth factor (IGF)-II and is an insulin secretagogue. Observational studies have linked elevated circulating preptin to metabolic dysfunction in humans; however, a causal role for preptin in metabolic dysfunction has not been established. Additionally, preptin can promote osteoblast proliferation and differentiation, suggesting a link with skeletal health. We previously described a global preptin knockout (KO) model. In this study, we sought to uncover the impact of preptin KO in mice on the response to a moderately high-fat diet (HFD) and low-fat diet (LFD). HFD groups had higher weight and fat mass gain, lower trabecular and cortical bone volume and fracture load, and higher liver triglycerides. In males, preptin deficiency led to lower blood glucose than wild-type (WT) mice under LFD conditions. This was accompanied by differences in bone microarchitecture, including lower trabecular bone volume fraction, trabecular number, and lower cortical thickness. These differences were absent in female mice, although KO females had a HFD-driven increase in fat mass and liver triglycerides that was absent in WT mice. Female WT mice had increased glucose-stimulated insulin secretion under HFD conditions that was absent in female KO mice. Overall, preptin may have a detrimental impact on metabolism and a positive impact on bone health in male mice and may protect against liver fat storage in females while enabling islet compensation under HFD conditions. When we consider that serum preptin levels are elevated in humans of both sexes in pathological states in which insulin levels are elevated, the impact of preptin on comorbidity risk needs to be better understood. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Circulating serum preptin levels in women with polycystic ovary syndrome: A systematic review and meta-analysis.

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder with complex pathogenesis and metabolic complications, such as insulin resistance. Among the new markers, preptin seems to play a significant role in metabolic disorders. This meta-analysis was conducted to determine the relationship between circulating preptin levels and PCOS. A systematic review and meta-analysis was performed to identify relevant articles in electronic databases such as PubMed, Web of Science, Scopus, Cochrane, EMBASE, and the Google Scholar search engine, using a predefined search strategy. A random-effects model was used to combine standard mean difference (SMD) and 95% CI to compare results between groups. Meta-regression and subgroup analysis were also performed to reveal the sources of heterogeneity. The meta-analysis encompassed a total of 8 studies and 582 participants. The results indicate a statistically significant association between PCOS and serum preptin levels, with a pooled standardized mean difference (SMD = 1.35; 95% CI]: 0.63-2.08; p 0.001). Further analysis suggested a significant difference in serum preptin levels between women with PCOS and higher homeostatic model assessment for insulin resistance ratio (SMD = 2.40; 95% CI: 1.17-3.63; p 0.001) within the subgroup. Our meta-analysis shows that increased serum preptin levels are associated with PCOS, suggesting that preptin may be related to the pathogenesis of PCOS and may be recognized as a novel diagnostic biomarker for PCOS. However, further studies are needed to confirm our results.

Maternal serum preptin levels in the pathogenesis and diagnosis of Gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) is a metabolic disorder that occurs during pregnancy that increases both maternal and fetal mortality and morbidity. It was investigated whether there is a change in circulating levels of preptin, a new peptide secreted from pancreatic beta cells, due to GDM in pregnant women. The relationship between serum preptin levels with insulin and other metabolic parameters was also evaluated in these subjects. Eighty-five patients diagnosed as GDM and 89 healthy pregnant women with 75 mg oral glucose tolerance test (OGTT) was assessed in terms of serum preptin levels. The serum preptin levels of the GDM group were significantly higher than those of the control group (p=0.001; p < 0.01). For the cutoff value of preptin measurement of 335.3 ng/L, the sensitivity was 97.65%, specificity was 87.64%, positive predictive value was 88.3% and negative predictive value was 97.5%. The risk of developing the disease is 294.273 times higher in patients with preptin level of 335.3 and above. We think that the reason for the increase in serum preptin levels in GDM is probably the response to glucose. The current results indicate that preptin plays an important role in elucidating the pathology of GDM. In addition, the search for a practical marker for the diagnosis of GDM suggests that the measurement of preptin level is promising.

An assesment of relationship between serum preptin levels and anti-mullerian hormone in infertile womens with polycystic ovary syndrome

An assesment of relationship between serum preptin levels and anti-mullerian hormone in infertile womens with polycystic ovary syndrome

Association of circulating preptin with non-alcoholic fatty liver disease: A case-control study

Background/Aim: Non-alcoholic fatty liver disease (NAFLD) is the hepatic component of metabolic disorders and identifying patients with a high risk of fibrosis is crucial. A scoring system, the FIB-4 score, based on clinical and biochemical parameters was developed to predict fibrosis. NAFLD is associated with various peptide hormones. However, the relationship of preptin, a newly discovered peptide critical for regulating energy metabolism, with NAFLD remains unclear. Therefore, we aimed to determine the relationship of preptin with NAFLD and evaluate whether there was an association between serum preptin levels and FIB-4 score. Methods: In this prospective study, serum biochemical parameters and serum preptin levels of 51 patients with grade 2-3 hepatosteatosis proven by ultrasonography and 35 healthy controls with similar demographic characteristics were compared. Serum preptin levels were measured using ELISA. The FIB-4 scores were calculated and recorded. Results: The serum preptin levels were higher in the NAFLD group than in the control cases (P<0.001). Among the patients, the sensitivity, specificity, positive predictive, and negative predictive values of preptin above a cut-off value of ≥62.3 were 85.7%, 56.9%, 85.3%, and 57.7%, respectively, with an accuracy of 68.6%. The preptin level was negatively correlated with the FIB-4 score and AST in the patient group (P=0.004 and P=0.014, respectively). The linear regression model revealed that there was a significant relationship between the FIB-4 score and preptin (P<0.05). Each 1 unit increase in the FIB-4 score induced a decrease of 86.37 units in preptin values (R²=%8.5). Conclusion: We demonstrated that the serum preptin levels were higher in patients with NAFLD than healthy individuals and negatively correlated with the FIB-4 score and AST levels. Preptin may have a role in the pathogenesis of NAFLD, is likely to distinguish patients with mild and severe liver damage and may be a useful marker in predicting a high risk for progression to fibrosis. Further studies establishing a stratification system including plasma preptin level and the FIB-4 score and its verification with liver biopsies are required.

Cord blood and maternal serum preptin and irisin concentrations are regulated independently in GDM.

The aim of this study is to examine the maternal serum and cord blood irisin and preptin levels in gestational diabetes mellitus (GDM) and correlate their levels with demographic and biochemical parameters. A total of 21 pregnant women with GDM and 21 BMI and age-matched pregnant women without GDM were included in the study. They underwent 50 g glucose challenge test (GCT) between 24-28th gestational weeks. Women with a GCT result higher than 140 mg/dl received 100 g oral glucose tolerance test (OGTT). Detection of one of the following criteria after OGTT was accepted as GDM: fasting plasma glucose level 92 mg/dL; 1-h plasma glucose level 180 mg/dL; and 2-h plasma glucose 153 mg/dL. Correlation between metabolic parameters and cord blood and maternal serum preptin and irisin levels in GDM and non-GDM subjects were analyzed. Maternal serum preptin values of GDM subjects were similar to the serum preptin values of non-GDM control subjects (123.12±34.3 pg/mL vs. 112.02±12.0 pg/mL, p<0.23). Cord blood preptin levels of GDM (64.3±1.09 pg/mL vs. 123.12±34.3 pg/mL, p<0.03) and non-GDM subjects (59.2±021 pg/mL vs. 112.02±12.0 pg/mL, p<0.02) were significantly lower than the maternal serum preptin values. Serum preptin levels of GDM group were positively correlated with HOMA-IR (r=0.33, p<0.04), but not with other parameters. Maternal serum irisin levels in the GDM group were lower than the non-GDM control group (5.32±0.44 µg/mL vs. 7.74±4.52 µg/mL, p<0.01). Cord blood irisin concentrations were found similar in women with GDM and non-GDM subjects (4.91±3.12 µg/mL vs. 5.01±2.14 µg/mL, p<0.14). Cord blood irisin levels of GDM subjects were similar to maternal serum irisin levels (4.91±3.12 µg/mL vs. 5.32±0.44 µg/mL, p<0.57). We found positive correlation between irisin concentration and fasting insulin, HOMA-IR, and BMI in women with GDM. In subgroup analysis of 6 patients using insulin treatment, serum and cord blood irisin and preptin levels were similar to those that did not use insulin. Maternal serum and cord blood preptin and irisin concentrations are regulated independently in women with GDM.

The Relationship Between Insulin Resistance and Serum Preptin Level

Objectives: Preptin is derived from e-peptide of proinsulin-like growth factor II, is present in islet β-cell granules and is co-secreted with insulin in response to glucose. Studies have suggested that preptin plays a role in glucose and lipid metabolism. In this study, we have investigated the serum preptin levels in patient with insulin resistance (IR) and by this way, we aimed to define the role of preptin as a parameter in early diagnosis and monitoring progression of diabetes. Materials and Methods: The study included 49 IR patients and 37 healthy controls. The presence of IR was based on the Homeostatic model of assessment- insulin resistance (HOMA-IR) level of 2.7 or higher. Fasting plasma samples were obtained from the patients and the control group. The serum levels of preptin were measured with an Enzyme-Linked Immuno Sorbent Assay (ELISA)kit. Results: The IR patients had higher fasting insulin, HOMA-IR and triglyceride levels than the control subjects (p < 0.01). And the serum levels of preptin were significantly higher in IR patients than in the healthy controls (492.00±289.23 and 98.41±50.64 respectively; p<0.01). They showed a positive correlation with the HOMA-IR (r=0.43; p<0.01), the fasting insulin level (r=0.64; p<0.001), body mass index count (r=0.41; p<0.01) and triglyceride level (r=0.26; p<0.05). Conclusion: The serum preptin level was higher in patients with IR. These findings demonstrate that there is a potential link between preptin and glucose-lipid metabolism. In conclusion, high preptin levels in patients with insulin resistance suggest that preptin may play a role in the pathogenesis of insulin resistance.

The beneficial effect of electro acupuncture on obesity may be associated with irisin, nesfatin-l and preptin levels

The action mechanism of acupuncture, one of the alternative methods used in obesity treatment, is unknown. The purpose of this study was to investigate the effect of electro acupuncture on weight loss and whether acupuncture treatment can change circulating levels of irisin, nesfatin-l and preptin, which have been discovered in recent years and plays an important role in nutrition and energy metabolism. Irisin, a newly discovered myokine, is associated with increased energy consumption and has a potential role in obesity. Preptin, present in islet b-cells of pancreas and associated with the carbohydrate metabolism, nesfatin1 is an anorexogenic peptide composed of 82 amino acids and regulates food intake by modulating neuropeptides in feeding centers in the brain. These three new hormones regulate energy intake and expenditure and preserve energy homeostasis and composition. In this study 4 weeks old Sprague Dawley male rats (n=16) were randomly divided into 2 groups which were the control (C): normal diet and obese (0): high fat diet (HFD) groups. 105 After 16 weeks which obesity was developed, electroacupuncture (EA) was performed to rats once in every second days for 3 times weekly for four consecutive weeks. EA was applied bilaterally to Zusanli (ST36), Bai Hui (Du20), He Gu (Li4), Tianshu (ST25) and Sanyinjiao (SP6) acupoints in animals to both groups. Blood was collected before and after EA and serum irisin, nesfatin-l and preptin levels were analyzed by ELISA (Enzyme-InducedImmunosorbent Analysis) method. After four week EA treatment, there was sginificant decrease of the average body weight in both groups rats. There were increases in the serum nesfatin-l and preptin levels in the both groups after acupuncture. A decrease was observed in the irisin levels in obese group, but an increase in the control group. These findings suggest that electroacupuncture may help to weight loss due to its effects on some important metabolic hormones such as irisin, nesfatin-l and preptin only for a few weeks. It is thought that the changes of these hormones levels may playa role in beneficial effect of acupuncture used in the treatment of human obesity. The application of EA in the treatment of obesity is very effective, which may have led to weight loss by altering these hormone levels in obese people.

Patatin-like phospholipase domain containing 3-gene (adiponutrin), preptin, kisspeptin and amylin regulates oocyte developmental capacity in PCOS

This study was planned to test whether follicular fluid (FF) levels of patatin-like phospholipase domain containing 3-gene (PNPLA3:adiponutrin), preptin, kisspeptin, and amylin change in polycystic ovarian syndrome (PCOS). A total of 40 infertile volunteers undergoing IVF/ICSI were included in the study. They were divided into two groups as PCOS (n=20) and control group without PCOS (n=20). The controls were recruited from subjects with a poor ovarian response. The PCOS and control participants were matched according to their body mass index (BMI). Each group of participants underwent ovarian stimulation with GnRH antagonist protocol. Blood and FF samples of one dominant follicle were obtained from each subject during the oocyte pick-up. FF and serum levels of PNPLA3, preptin, kisspeptin and amylin were measured through ELISA. Amylin and adiponutrin median values were not different according to study groups (p&gt;0.05). FF-preptin median values in the control group were similar to the serum preptin values of control and PCOS groups (Z=0.970, p=1.000 and Z=2.631, p=0.051, respectively). Medians of the serum preptin in control and PCOS groups were the same (Z=1.649; p=0.595). FF-preptin median values of PCOS group were significantly lower than the preptin median values of the control group. Serum preptin levels were positively correlated with HOMA-IR, but not with pregnancy rates and the number of retrieved oocytes. Serum kisspeptinlevels were negatively correlated with the number of retrieved oocytes and pregnancy rates. While amylin and adiponutrin have no role in the folliculogenesis, kisspeptin and preptin work together for regulating follicle developmental capacity in PCOS.

Serum Preptin and Amylin Levels with Respect to Body Mass Index in Polycystic Ovary Syndrome Patients.

BackgroundPreptin and amylin are pancreatic hormones which participate in glucose homeostasis. This study aimed to evaluate how serum preptin and amylin levels are altered in polycystic ovary syndrome (PCOS) patients and healthy women based on BMI groups (<25 kg/m2 and ≥25 kg/m2).Material/MethodsThis was a prospective randomized control study of 40 PCOS patients and 40 healthy women who were matched with respect to BMI (<25 kg/m2 and ≥25 kg/m2).ResultsWhen compared to the healthy women, PCOS patients had significantly higher ovarian volumes, Ferriman-Gallwey scores, and free and total testosterone levels, but significantly lower amylin concentrations (p=0.001, p=0.001, p=0.049, p=0.021, and p<0.001, respectively). Both the normal-weight and overweight PCOS patients had significantly lower amylin levels than the normal-weight and overweight controls (p<0.001, p=0.009, p=0.001, and p=0.001, respectively). Amylin levels were negatively and significantly correlated with the Ferriman-Gallwey scores (r=−0.272, p=0.001) and ovarian volume (r=−0.206, p=0.007). Serum preptin levels were not elevated in either group.ConclusionsSerum preptin levels are statistically similar in PCOS patients and BMI-matched healthy controls. Serum amylin levels are significantly higher in healthy controls than PCOS patients whether they are slim or overweight. These findings suggest the presence of mechanisms that can prevent the elevation in serum amylin concentrations that can occur in response to the impaired glucose metabolism in PCOS patients.

Preptin in women with polycystic ovary syndrome

Introduction: Polycystic ovary syndrome (PCOS) patients, frequently develop metabolic complications, such as insulin resistance (IR), impaired carbohydrate metabolism, dyslipidemia, obesity. Among the new markers responsible for metabolic disorders, preptin seems to be of great significance. Material: One hundred and thirty-four women aged 17–45 were enrolled. PCOS was diagnosed in 73 women on the basis of ESHRE-ASRM criteria. Non-PCOS group consisted of 61 women with regular menstruation matched for nutritional status. Methods: All women underwent anamnesis, physical examination, anthropometric measurements, the abdominal ultrasound examination, and dual energy X-ray absorptiometry (DXA). Serum adropin levels were determined by ELISA. Biochemical and hormonal (testosterone, androstenedione, LH, FSH, estradiol) measurements were also performed. Insulin resistance indices (HOMA, QUICKI, Matsuda) and free androgen index (FAI) were calculated with the test results according to the standard formula. For all comparisons, statistical significance was defined by p ≤ .05. Results: Serum preptin levels were significantly higher in the PCOS group. No significant correlations between preptin level and metabolic and hormonal markers were observed. The logistic regression analysis demonstrated that serum preptin level was an independent factor differentiating the two groups. Conclusions: Serum preptin levels were significantly higher in women with PCOS compared with controls. This peptide might be an independent predictor of PCOS in the future.

Investigation of the relation between bone mass density and serum preptin levels in pre- and postmenopausal women.

Preptin is a peptide hormone co-secreted with insulin and amylin from pancreatic β cells. It has been demonstrated to have osteogenic effects both in vitro and in vivo. In the present study, serum preptin levels were measured in pre- and postmenopausal women with similar body mass indexes (BMIs) to elucidate its link with bone mineral density (BMD). Sixty women (30 premenopausal and 30 postmenopausal) with low bone mineral density were studied. The BMD scores, serum preptin levels and serum estradiol levels were measured. The correlation between serum preptin and estradiol levels with BMD was assessed. Serum preptin and estradiol levels were significantly lower in the postmenopausal women than the premenopausal subjects [2102.27±918.66 vs. 2667.30±940.41ng/L (P<0.05) and 39.32±31.74 vs. 99.24±49.24pg/ml (P<0.001), respectively]. The serum preptin levels had weak positive (albeit statistically significant) correlations with estradiol (r=0.271, P=0.036), femur neck BMD (r=0.233, P=0.035) and total hip BMD (r=0.287, P=0.031), but no correlation was observed between serum preptin levels and L1-4 lumbar spine BMD (r=0.136, P=0.474). The findings of the present study suggest that serum preptin levels in women decrease after menopause and have a positive correlation with estradiol, femoral and total hip BMDs.

Lower circulating preptin levels in male patients with osteoporosis are correlated with bone mineral density and bone formation

BackgroundSerum preptin levels among subjects with different bone mineral densities (BMD) were measured and investigated to determine the correlation between BMD and bone-metabolic markers.MethodsApproximately 52 elderly male patients with osteoporosis, 50 elderly men with osteopaenia, and 31 age-matched normal bone mass controls participated in the study. The serum preptin levels and bone metabolic markers were measured by enzyme-linked immunosorbent assay. The relationships between preptin levels, BMD, and metabolic parameters were also assessed.ResultsThe serum preptin level was the lowest in the osteoporosis group and positively correlated with BMD. All the bone formation markers in the osteoporosis and osteopaenia groups were significantly reduced compared with those in the normal group. Serum preptin level was positively correlated with all the bone formation markers, whereas no correlation was observed with the bone resorption marker TRACP-5b.ConclusionsSerum preptin levels are decreased in osteoporosis and osteopaenia patients and positively correlated with BMD. Therefore, preptin is involved in the pathogenesis of osteoporosis, probably through bone formation rather than bone resorption.

The relationship between polycystic ovary syndrome, glucose tolerance status and serum preptin level

BackgroundPolycystic ovary syndrome (PCOS) is linked to obesity, impaired glucose tolerance and diabetes. Recently, studies have found that preptin enhances insulin secretion in rats and might play a role in the pathogenesis of diabetes and PCOS in humans. The aim of this study was to evaluate the relationship between PCOS, glucose tolerance status, and serum preptin level.MethodsThis study was conducted in a university-affiliated hospital from October 2010 to August 2011. Anthropometric parameters, sex hormone concentrations, blood pressure, lipid profiles, fasting glucose and insulin, 2-h blood glucose after glucose overloaded (2hOGTT), glycosylated haemoglobin (HbA1c), homeostasis model assessment-insulin resistance index (HOMA-IR), and serum preptin of the samples were analyzed.ResultsSixty-three PCOS patients, including 33 women with normal glucose tolerance (NGT) and 30 women with impaired glucose tolerance (IGT), and 63 patients without PCOS, including 35 women with NGT and 28 women with IGT were recruited in this study. For patients with and without PCOS, women with IGT had higher serum preptin levels compared with women with NGT. Preptin levels in PCOS patients were higher compared with patients without PCOS, but the difference was not significant. Fasting serum preptin levels correlated positively with TG, SBP, DBP, FBG, 2hOGTT, and HOMA-IR in simple regression analysis of the pooled data. While in multiple stepwise regression analysis, preptin levels were independently related with glucose tolerance, but not with PCOS.ConclusionsIrrespective of PCOS status, women with IGT had higher serum preptin levels compared with women with NGT. Preptin levels are related with glucose tolerance status, but not with PCOS status.

An appraisal of serum preptin levels in PCOS

Plasma preptin levels were higher in women with PCOS compared with the control group (mean±SD, 823.2±140.7 vs. 324.9±147.3 pg/mL). This article suggests a potential role of preptin in the pathogenesis of PCOS.