OBJECTIVES

In Asia, younger individuals (below age 45) are diagnosed to have type 2 diabetes with increased rates of obesity defined by lower BMI yet with greater visceral adiposity (waist circumference and waisthip ratios). The prevalence data on type 1 diabetes is not well established, considered to be low, but is seen to be increasing as well. This changing phenotype therefore, presents a clinical dilemma in terms of correctly classifying diabetes and deciding on the consequent appropriate treatment. Distinguishing type 1 from type 2 diabetes has become more difficult with type 2 diabetes dramatically increasing in young adults and children. This study aims to define the characteristics of diabetes among young adults in the Philippines to provide a basis for appropriate management amidst changes in diabetes phenotypes seen globally.

METHODS

In this cross-sectional analytic study, we characterized the demographic, metabolic, and autoimmune features of diabetes among young adult Filipinos aged 18 to 45 years old consulting at a tertiary referral center in Manila, Philippines. Baseline serum A1c, FBS, 75-g oral glucose tolerance test, insulin, serum C-peptide, insulin autoantibodies, leptin, adiponectin, lipid profile, and thyroid function tests were obtained from the participants and analyzed. The homeostasis model assessment (HOMA) was used to estimate the insulin sensitivity.

RESULTS

A total of 348 patients with diabetes were included, with females comprising two-thirds of the participants. The mean age at diagnosis of diabetes was 35.9±7.22 years. The mean BMI was 28.12 kg/m2, with median waist to hip ratio (WHR) of 0·93. Metabolic syndrome was found in 60% of participants and 67.82% were obese by body mass index. The mean A1c was 9.07±2.52%. Good glucose control (A1c less than 7.0%) was seen in 23% of participants  while nearly half (48%) had HbA1c which was >9.0%. The median levels of fasting insulin and C-peptide were 12.62 (range 1.33–90.42) mIU/L and 0.78 ng/mL (range 0–16.2), respectively. 

Included participants were diagnosed with diabetes within a year and as such, majority did not have any micro- or macrovascular complications. The most common diabetes complication was sensory neuropathy detected by monofilament testing, which was found in 28% of participants, followed by non-proliferative diabetic retinopathy in 13%. A history of previous diabetic ketoacidosis was found in 10 patients (2.87%). Glutamic acid decarboxylase (GAD) and insulin auto-antibodies were found in 3.2% and 19.3% of participants, respectively. Approximately half (51.73%) of the participants were insulin resistant by HOMA-IR.

CONCLUSION

In contrast with Caucasians and other Asians, diabetes among young Filipino adults is associated with lower BMI but with a similarly high visceral adiposity as shown by an elevated WHR. Metabolic syndrome with insulin resistance as defined by a variety of indices is predominant. Type 1 diabetes with autoantibodies occur in only a small fraction of this population. Data derived from this work can provide a framework for cluster analysis towards personalized management specific to this population.

Human ; Acids ; Adiponectin ; Adiposity ; Adult ; Aged ; Antibodies ; Asia ; Asian ; Asian Continental Ancestry Group ; Autoantibodies ; Body Mass Index ; C-peptide ; Carboxy-lyases ; Child ; Cluster Analysis ; Demography ; Diabetes Complications ; Diabetes Mellitus ; Diabetes Mellitus, Type 1 ; Diabetes Mellitus, Type 2 ; Diabetic Ketoacidosis ; Diabetic Retinopathy ; Diagnosis ; Fasting ; Female ; Glucose ; Glucose Tolerance Test ; Glutamate Decarboxylase ; Glutamic Acid ; Insulin ; Insulin Resistance ; Ketosis ; Leptin ; Lipids ; Metabolic Syndrome ; Obesity ; Patients ; Peptides ; Phenotype ; Philippines ; Population ; Prevalence ; Serum ; Therapeutics ; Thyroid Gland ; Thyroid Function Tests ; Young Adult

Abstract Introduction: Type 2 diabetes mellitus (T2DM) is a major global health concern characterized by insulin resistance, hyperglycemia, and chronic inflammation. Interest in natural adjunctive therapies has increased, particularly in mangosteen (Garcinia mangostana), which contains xanthone compounds in the peel with potential antidiabetic properties. Methods: This systematic review followed PRISMA 2020 guidelines. Literature searches were conducted using PubMed, Google Scholar, and ClinicalKey up to December 2022 for studies assessing mangosteen peel extract (MPE) or α-mangostin in diabetic human subjects. Eligible studies included randomized controlled and quasi-experimental trials reporting glycemic or metabolic outcomes. Risk of bias was evaluated using the Cochrane RoB tool. The primary result of this study is to evaluate the effects of mangosteen peel extract supplementation on key glycemic outcomes in patients with T2DM, specifically fasting blood glucose (FBG), HOMA-IR, and HbA1c. Results: A total of two studies (n=2) met the inclusion criteria. A randomized controlled pilot trial reported significant improvement in insulin sensitivity (HOMA-IR −53.2% vs −15.2%; p = 0.004) after 26 weeks of standardized mangosteen extract. A small quasi-experimental study reported a significant reduction in FBG following 7 days of mangosteen peel decoction. Discussion: Limited clinical evidence indicates that mangosteen peel extract may improve insulin sensitivity and lower fasting glucose in T2DM. However, the conclusions are limited by the small number of available studies, the short follow-up duration in one trial, and variability in extract preparation. Conclusion: Mangosteen peel extract demonstrates promising glycemic benefits, including improved insulin sensitivity and reduced fasting glucose. However, the available evidence remains limited by small sample sizes, short follow-up periods, and heterogeneity in extract formulations. Larger randomized controlled trials using standardized preparations are required before clinical recommendations can be made.
Garcinia mangostana ; mangosteen peel extract ; &alpha ; -mangostin ; type 2 diabetes mellitus ; insulin resistance ; oxidative stress

Introduction: Insulin resistance and progressive beta-cell dysfunction are key components of the pathophysiology of type 2 diabetes mellitus (T2DM). The triglyceride-to-highdensity lipoprotein cholesterol (TG/HDL) ratio has been widely used as a marker of insulin resistance. In addition, testosterone deficiency has been associated with adverse metabolic profiles and T2DM. However, the relationship between testosterone levels, insulin resistance, and betacell function in patients with T2DM remains incompletely understood. Methodology: A cross-sectional study was conducted involving 25 male patients with T2DM attending the diabetic clinic at Dr. Mohammad Hoesin General Hospital. Serum testosterone, C-peptide, TG, and HDL levels were obtained from routine clinical data. The TG/HDL ratio was calculated as an index of insulin resistance. Normality was assessed using the Shapiro–Wilk test, and due to the non-normal distribution of key variables, Spearman correlation analysis was applied. Results: A strong inverse correlation was observed between testosterone levels and TG/HDL ratio (r = -0.860, p <0.001), indicating that higher insulin resistance was associated with lower testosterone levels. In addition, TG/HDL ratio showed a strong negative correlation with C-peptide levels (r = -0.741, p <0.001), suggesting reduced beta-cell function in the presence of increased insulin resistance. Conclusion In patients with T2DM, increased insulin resistance is strongly associated with lower testosterone levels and reduced beta-cell function. These findings highlight the interaction between metabolic dysfunction and hormonal status in middle-aged and elderly patients with T2DM
Diabetes Mellitus, Type 2 ; Insulin Resistance ; Testosterone

Introduction: Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome caused by tumor secretion of insulin-like growth factor-2 (IGF-2), leading to recurrent hypoinsulinemic hypoglycemia. It is most commonly associated with large mesenchymal tumors, such as solitary fibrous tumor, particularly those arising from the pleura or lungs. This phenomenon, also known as Doege–Potter syndrome, may precede tumor detection or signal tumor recurrence. We report a striking case of late malignant recurrence presenting solely with hypoglycemia after a decade of remission. Case: A 68-year-old female was initially presented in 2016 with respiratory symptoms and recurrent symptomatic fasting and post-prandial hypoglycemia, and was found to have a large left upper lobe mass. Tumor resection in 2017 resulted in complete resolution of hypoglycemia. She remained asymptomatic for several years. In 2023, she developed recurrent hypoglycemia without respiratory or constitutional symptoms. Biochemical evaluation demonstrated hypoinsulinemic hypoglycemia with suppressed insulin and C-peptide, low IGF-1, and markedly elevated IGF-2, resulting in an IGF-2:IGF-1 ratio of 25, consistent with IGF-2-mediated NICTH. Computed tomography imaging revealed a large left thoracic mass with invasion into the intercostal muscles and diaphragm with extension toward the stomach, associated with contralateral lung nodules and possible liver metastases, suggesting recurrent malignant disease. Hypoglycemia improved with glucocorticoid therapy, and the patient was referred for oncological assessment. Despite initiation of systemic chemotherapy, her disease progressed and she succumbed during treatment. Conclusion This case highlights several important lessons: Firstly, recurrent hypoinsulinemic hypoglycemia warrants evaluation for NICTH even in the absence of tumor-related symptoms. Secondly, solitary fibrous tumors may recur or undergo malignant transformation after prolonged disease-free intervals; and glucocorticoids provide effective metabolic control but do not alter oncologic prognosis. Long-term surveillance should be considered in patients with prior solitary fibrous tumors due to the risk of delayed recurrence and paraneoplastic complications.
Insulin-Like Growth Factor II ; Hypoglycemia ; Neoplasms

Introduction: Acromegaly is an endocrine disorder caused by excess growth hormone (GH), causing somatic overgrowth, multiple comorbidities, and premature mortality. It is confirmed biochemically by an elevated GH level, which is not suppressed post oral glucose tolerance test (OGTT). The serum level of insulin-like growth factor-1 (IGF-1) is recommended for diagnosis, monitoring, and screening, and a normal level effectively excludes the disease. We report a patient with acromegaly who presented with normal IGF-1. Case: A 21-year-old female, with no known medical illness, presented with a persistent, progressive headache and amenorrhea for the past 6 months. She also noticed a change in facial appearance and an increase in the size of her hands and feet. Blood parameters revealed raised GH level of >50 ng/mL, normal IGF-1 30.3 nmol/L (12.17–44.80), mildly raised prolactin 692 mIU/L, low am cortisol 62 nmol/L (166–507), thyroid-stimulating hormone of 0.63 mIU/L (0.27–4.20), free thyroxine 4 11 pmol/L (12–22), low follicle-stimulating hormone 0.90 IU/L, luteinizing hormone <0.30 IU/L, estradiol <18.4 pmol/L, and fasting blood sugar of 17.7 mmol/L with hemoglobin A1c 9%. In view of normal IGF-1 with a high index of suspicion for acromegaly, she underwent OGTT which showed unsuppressed GH. Magnetic resonance imaging pituitary showed sellar mass 2.4 × 2.9 × 2.1 cm with suprasellar extension as well as extension into the right cavernous sinus, suggestive of pituitary macroadenoma. She was diagnosed with acromegaly with secondary adrenal insufficiency and central hypothyroidism with hypogonadotropic hypogonadism, complicated with poorly controlled diabetes. She was started on thyroxine and hydrocortisone replacement and required basal bolus insulin of 1.3 u/kg/day. Repeated IGF-1 showed a raised value, 85.4 nmol/L, after optimization of diabetes. She underwent endoscopic transsphenoidal surgery with normalization of blood sugar post-surgery. Blood pressure was normal throughout. Conclusion False negative or normal IGF-1 levels may result in patients with hepatic or renal failure, hypothyroidism, malnutrition, use of oral estrogen, severe infection, and poorly controlled diabetes mellitus. Hence, a low or normal IGF1 does not exclude acromegaly in patients with a high index of suspicion and warrants further investigation.
Acromegaly ; Insulin-Like Growth Factor I

Introduction: Acromegaly is usually diagnosed by elevated age- and sex-adjusted insulin-like growth factor-1 (IGF-1) levels reflecting chronic growth hormone (GH) excess. IGF-1 is preferred as a screening biomarker due to its longer half-life and reduced pulsatility compared with GH. However, IGF1 levels may be disproportionately low or only modestly elevated in certain clinical contexts, leading to diagnostic uncertainty. Pituitary apoplexy is one such condition in which acute tumor hemorrhage or infarction may disrupt sustained GH secretion and attenuate IGF-1 production Case: A 48-year-old female with hypertension, type 2 diabetes mellitus, and dyslipidemia presented with a 2-day history of severe headache, vomiting, and visual disturbance, on a background of progressive acral enlargement over 2 years. Examination revealed coarse facial features, prognathism, enlarged hands, and cranial nerve involvement. Magnetic resonance imaging demonstrated an invasive sellar– suprasellar pituitary macroadenoma with optic chiasmal compression and cavernous sinus encasement. Intravenous dexamethasone was initiated pre-operatively due to a significant mass effect. Biochemical evaluation showed markedly elevated random GH levels (>50 ng/mL) with only mildly elevated IGF-1 at 1.19 times the upper limit of normal, below the threshold at which confirmatory oral glucose tolerance testing may be omitted according to current guidelines. Other pituitary axes suggested evolving hypopituitarism. During admission, she developed severe hyperglycemia with marked insulin resistance, requiring high-dose insulin therapy (approximately 1.5 U/kg/day). She underwent urgent transsphenoidal surgery, with histopathology confirming a pituitary neuroendocrine tumor with extensive hemorrhage and infarction, consistent with pituitary apoplexy. Postoperatively, GH levels were suppressed to <5 ng/mL, insulin requirements decreased markedly, and hormone replacement was initiated for secondary adrenal insufficiency and central hypothyroidism. Conclusion This case highlights that IGF-1 levels below conventional diagnostic thresholds do not exclude clinically significant acromegaly, particularly in the setting of pituitary apoplexy. Integration of clinical phenotype, GH levels, and imaging findings is essential to avoid diagnostic delay and ensure timely management.
Acromegaly ; Insulin Resistance ; Pituitary Apoplexy

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) and hypertension are common metabolic disorders, both closely associated with insulin resistance (IR), suggesting potential shared pathological mechanisms. This study aims to investigate the mediating role of IR in the relationship between hypertension and NAFLD, and to evaluate the applicability and modeling value of various IR surrogate indices in predicting NAFLD risk. METHODS: A total of 280 976 individuals who underwent health examinations at the Health Management Center of the Third Xiangya Hospital of Central South University between August 2017 and December 2021 were included. NAFLD was diagnosed based on abdominal ultrasound findings, and hypertension was defined according to the criteria of the Chinese Guidelines for the Management of Hypertension. Demographic information, anthropometric indices, and biochemical parameters were collected, and multiple IR surrogate indices were constructed, including the triglyceride-glucose index (TyG) and its derivatives, as well as the metabolic score for insulin resistance (METS-IR). Group comparisons were performed between hypertensive and non-hypertensive participants, as well as between NAFLD and non-NAFLD participants. Pearson correlation analysis was applied to assess the associations of metabolic parameters and IR indices with NAFLD. Furthermore, mediation models were constructed to explore the mediating role of IR in the "hypertension-NAFLD" relationship. Finally, parametric models and machine learning algorithms were compared to evaluate their predictive performance and value in assessing NAFLD risk in this population. RESULTS: The prevalence of NAFLD was significantly higher in hypertensive individuals than in non-hypertensive participants (63.61% vs 33.79%, P<0.001), accompanied by elevated IR levels and adverse metabolic features. Correlation analysis and variable importance rankings across multiple models consistently identified TyG-waist circumference (TyG-WC) and METS-IR as the IR indices most strongly associated with NAFLD. In mediation analysis, the TyG-WC pathway explained 32.03% of the total effect, and the METS-IR pathway explained 17.02%. Interaction analysis showed that hypertension status may attenuate the mediating effect of IR (all interaction estimates were negative). In prediction model comparisons, the simplified model incorporating sex, age, WC, TyG-WC, and METS-IR demonstrated good performance in the test set. Logistic regression and its regularized form (LASSO regression) achieved an accuracy of 0.83, receiver operating characteristic (ROC)-area under the curve (AUC) of 0.91, and a Brier score of 0.12, comparable to ensemble models (random forest and XGBoost), with consistently stable performance across different algorithms. CONCLUSIONS IR plays a significant mediating role in the association between hypertension and NAFLD, with TyG-WC identified as a key indicator showing strong mechanistic relevance and predictive value. Risk prediction models based on IR surrogate indices demonstrate advantages in simplicity and interpretability, providing empirical support for the early screening and individualized prevention of NAFLD in the general population.
Humans ; Non-alcoholic Fatty Liver Disease/complications* ; Insulin Resistance ; Hypertension/epidemiology* ; Male ; Female ; Middle Aged ; Risk Factors ; Adult ; Machine Learning ; Triglycerides/blood*

Parkinson's disease (PD), a chronic and common neurodegenerative disease, is characterized by the progressive loss of dopaminergic neurons in the dense part of the substantia nigra and abnormal aggregation of alpha-synuclein. Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by chronic insulin resistance and deficiency in insulin secretion. Extensive evidence has confirmed shared pathogenic mechanisms underlying PD and T2DM, such as oxidative stress caused by insulin resistance, mitochondrial dysfunction, inflammation, and disorders of energy metabolism. Conventional drugs for treating T2DM, such as metformin and glucagon-like peptide-1 receptor agonists, affect nerve repair. Even drugs for treating PD, such as levodopa, can affect insulin secretion. This review summarizes the relationship between PD and T2DM and related therapeutic drugs from the perspective of insulin signaling pathways in the brain.
Humans ; Parkinson Disease/drug therapy* ; Diabetes Mellitus, Type 2/pathology* ; Signal Transduction/physiology* ; Receptor, Insulin/metabolism* ; Animals ; Insulin Resistance/physiology* ; Insulin/metabolism*

Our research reveals the critical role of the suprachiasmatic nucleus (SCN) vasoactive intestinal peptide (VIP) neurons in mediating light-induced transient forgetting. Acute exposure to bright light selectively impairs trace fear memory by activating VIP neurons in the SCN, as demonstrated by increased c-Fos expression and Ca²⁺ recording. This effect can be replicated and reversed through optogenetic and chemogenetic manipulations of SCN VIP neurons. Furthermore, we identify the SCN → PVT (paraventricular nucleus of the thalamus) VIP neuronal circuitry as essential in this process. These findings establish a novel role for SCN VIP neurons in modulating memory accessibility in response to environmental light cues, extending their known function beyond circadian regulation and revealing a mechanism for transient forgetting.
Animals ; Vasoactive Intestinal Peptide/metabolism* ; Male ; Mice ; Neurons/metabolism* ; Suprachiasmatic Nucleus/physiology* ; Light ; Mice, Inbred C57BL ; Memory/physiology* ; Fear/physiology* ; Suprachiasmatic Nucleus Neurons/metabolism* ; Optogenetics ; Proto-Oncogene Proteins c-fos/metabolism*

The mandibular condyle is a critical growth center in craniofacial bone development, especially during postnatal stages. Postnatal condyle osteogenesis requires precise spatiotemporal coordination of growth factor signaling cascades and hierarchical gene regulatory networks. Plagl1, which encodes a zinc finger transcription factor, is a paternally expressed gene. We demonstrate that PLAGL1 is highly expressed in cranial neural crest cell (CNCC)-derived lineage cells in mouse condyles. Using the CNCC-derived lineage-specific Plagl1 knockout mouse model, we evaluate the function of PLAGL1 during postnatal mouse condyle development. Our findings show that PLAGL1 contributes significantly to osteoblast differentiation, and its deficiency impairs osteogenic lineage differentiation, which consequently disrupts mandibular condyle development. Mechanistically, insulin-like growth factor 2 (IGF2) in complex with IGF-binding proteins (IGFBPs) has been identified as the principal PLAGL1 effector responsible for osteogenic regulation during postnatal condyle morphogenesis. Plagl1 deficiency significantly downregulates the IGF2/IGFBP pathway, leading to disordered glucose metabolism, defective extracellular matrix organization, and impaired ossification. Exogenous IGF2 treatment rescues impaired osteoblast differentiation caused by Plagl1 deficiency. In conclusion, the PLAGL1-IGF2 axis is a critical regulator of osteogenesis during mandibular condyle development.
Animals ; Osteogenesis/genetics* ; Insulin-Like Growth Factor II/metabolism* ; Mice ; Transcription Factors/metabolism* ; Mice, Knockout ; Cell Differentiation ; DNA-Binding Proteins/genetics* ; Mandibular Condyle/growth & development* ; Osteoblasts/cytology* ; Signal Transduction ; Neural Crest/cytology*