Serum insulin and leptin levels in valproate-associated obesity

PURPOSE: Weight gain is an important adverse effect of valproate (VPA) therapy, and it is associated with hyperinsulinemia and hyperandrogenism in women with epilepsy. Leptin is considered a signaling factor regulating body weight and energy metabolism. In human subjects, obesity is in general associated with elevated serum leptin levels, suggesting decreased sensitivity to leptin. The present study aimed at evaluating the role of insulin and leptin in VPA-related obesity. METHODS: Body mass index (BMI) was calculated, and serum insulin and leptin levels were measured in 81 patients with epilepsy taking VPA and in 51 healthy control subjects. RESULTS: Forty (49%) of the patients taking VPA and 25 (49%) of the control subjects were obese. The mean insulin levels were higher in VPA-treated patients than in the control subjects despite similar BMI values, when all subjects were included in the comparison. Both obese male and female patients taking VPA had higher serum insulin levels than the respective control subjects with similar BMI values. Serum insulin levels also were higher in lean male and lean female patients compared with the lean control subjects of same sex. Serum leptin levels did not differ between the VPA-treated patients and the control subjects. CONCLUSIONS: Both obese and lean patients taking VPA for epilepsy have hyperinsulinemia, suggesting development of insulin resistance. This may be one of the factors leading to weight gain during VPA treatment. However, the results of the present study do not suggest an independent role for leptin in the pathogenesis of VPA-related obesity.     

Valproate, weight gain and carbohydrate craving: a gender study.

PURPOSE: To compare the incidence and magnitude of weight gain associated with valproic acid (VPA) monotherapy in male and female epilepsy patients and to determine possible gender-specific differences in frequency of carbohydrate craving, body-composition, glucose homeostasis and lipid metabolism. METHODS: Epilepsy patients on VPA monotherapy were consecutively recruited at the outpatient clinic of the Department of Neurology, Innsbruck Medical University. Weight gain during VPA-therapy, frequency of carbohydrate craving and physical exercise, sociopsychological problems and family history for diabetes were obtained from all patients. Clinical data also comprised body-impedance analysis, body mass index and waist-to-hip ratio. Morning fasting blood samples were drawn to determine serum leptin, glucose and lipid concentrations, as well as insulin, C-reactive protein and TNF-alpha. RESULTS: One hundred and six patients (55 women) were enrolled in the study. Significant weight gain was seen during VPA-therapy in both genders (each p<0.001) with women experiencing increment of weight more frequently and more pronounced than did men. Analyses of patients who gained weight during VPA-therapy revealed significantly higher serum leptin concentrations in women than in men (p<0.001). Women also revealed significantly higher high-density lipoprotein-cholesterol and lower triglyceride concentrations than men (p=0.004 and 0.014, respectively). Frequency of carbohydrate craving was 25.8% in women and 14.3% in men. More women tried to lose or control weight through diet than did men (22.6% versus 7.1%). Moreover, weight gain as a sociopsychological problem was more numorous in women than in men. CONCLUSION: Women are more prone to gain weight during VPA therapy though higher frequency of diet and sociopsychological burden than men, which might possibly be related to leptin-resitance and a higher frequency of carbohydrate craving.     

Adiponectin and visfatin concentrations in children treated with valproic acid

Chronic antiepileptic therapy with valproic acid (VPA) is associated with increased body weight and insulin resistance in adults and children. Attempts to determine the underlying pathophysiologic mechanisms have failed. Adipocytokines have recently been defined as a link between glucose and fat metabolism. We herein demonstrate that VPA-associated overweight is accompanied by lower adiponectin and higher leptin concentrations in children. The absence of any relationship with visfatin concentration does not suggest a role of this novel insulin-mimetic hormone in VPA-associated metabolic alterations. Therefore, adiponectin and leptin but not visfatin may be considered as potential regulators of glucose and fat metabolism during VPA-therapy.     

Impact of leptin on memory function and hippocampal structure in mild cognitive impairment

Metabolic changes have been suggested to contribute to dementia and its precursor mild cognitive impairment (MCI), yet previous results particularly for the “satiety hormone” leptin are mixed. Therefore, we aimed to determine if MCI patients show systematic differences in leptin, independent of sex, adipose mass, age, and glucose and lipid metabolism, and whether leptin levels correlated with memory performance and hippocampal integrity. Forty MCI patients (20 females, aged 67 years ± 7 SD) were compared to 40 healthy controls (HC) that were pair‐wise matched for sex, age, and body fat. Memory performance was assessed using the auditory verbal learning test. Volume and microstructure of the hippocampus were determined using 3T‐neuroimaging. Fasting serum markers of leptin, glucose and lipid metabolism, and other confounding factors were assayed. MCI patients, compared with HC, showed lower serum leptin, independent of sex, age, and body fat (P < 0.001). Glucose and lipid markers did not attenuate these results. Moreover, MCI patients exhibited poorer memory and lower volume and microstructural integrity within hippocampal subfields. While leptin and memory were not significantly correlated, mediation analyses indicated that lower leptin contributed to poorer memory through its negative effect on right hippocampus volume and left hippocampus microstructure. We demonstrated that MCI is associated with lower serum leptin independent of sex, age, body fat, glucose, and lipid metabolism. Our data further suggest that inefficient leptin signaling could partly contribute to decreases in memory performance through changes in hippocampus structure, a hypothesis that should now be verified in longitudinal studies. Hum Brain Mapp 37:4539–4549, 2016. © 2016 Wiley Periodicals, Inc.     

Increased oxidative stress in epileptic children treated with valproic acid

PURPOSE: To determine influence of Valproic Acid (VPA) treatment on oxidative status in non-obese and overweight epileptic children. METHODS: A prospective study was conducted at the Departments of Pediatrics, University of Chieti and Bologna. Thirty-one epileptic children were studied before and after 1 year of therapy with VPA. Also 31 sex-, age- and BMI-matched healthy controls were evaluated. Insulin and glucose serum levels and plasma Vitamin E, Lag phase and Malondialdehyde (MDA) levels were determined. RESULTS: Before the beginning of VPA therapy, insulin and glucose serum values and plasma Vitamin E, Lag phase and MDA levels were normal in all subjects. At the end of follow-up, 11 (35.5%) epileptic patients developed obesity. In obese VPA treated patients, we found lower serum levels of antioxidant (Vitamin E, p<0.001) and higher levels of oxidant markers (MDA, p<0.001; Lag phase, p<0.001) compared to VPA-treated non-obese patients and controls. CONCLUSION: After 1 year of VPA therapy oxidative stress occurs only in overweight children. This increase in the levels of oxidant markers, probably caused by obesity, might contribute to the development of endothelial dysfunction and atherosclerosis later in life.     

血清瘦素水平与糖尿病合并脑梗死关系的临床研究

目的探讨血清瘦素水平与2型糖尿病(DM)合并脑梗死的关系。方法应用酶联免疫法测定128例(非肥胖者62例,肥胖者66例)DM患者(其中合并脑梗死者63例)的血清瘦素水平,并对合并脑梗死者的瘦素水平、血脂、血糖、血压、体质量指数等进行相关分析。结果(1)DM肥胖者血清瘦素水平高于非肥胖者(P<0·001);(2)女性血清瘦素水平[(13·00±5·20)ng/ml]显著高于男性[(6·84±2·57)ng/ml](P<0·001);(3)DM合并脑梗死者血清瘦素水平高于无脑梗死者(P<0·05);(4)采用Logistic逐步回归分析发现血清瘦素水平、高血脂、高血糖、高血压、体质量指数等为脑梗死发生的危险因素。结论2型DM合并脑梗死血清瘦素水平升高,瘦素可能在2型DM脑梗死的发病中起一定作用。     

Leptin in adolescent idiopathic scoliosis – A meta-analysis

To compare the serum levels of leptin and soluble leptin receptor (sOB-R) with adolescent idiopathic scoliosis (AIS) girls and controls through meta-analysis. The MEDLINE via PubMed, Cochrane, Scopus, and EMBASE database, from the earliest available date of indexing between January 2010 and January 2019, were searched for comparative studies evaluating serum levels of leptin and sOB-R in AIS girls. Two authors performed the data extraction independently. Any discrepancies were resolved by a consensus. Six comparative studies were identified. There was no statistically significant difference in terms of leptin between AIS girls and control [p = 0.19, WMD = −2.06 (−5.14, 1.03) ng/mL]. However, the sOB-R level was significantly higher [p < 0.00001, WMD = 2.85 (1.81, 3.88) ng/mL] and the free leptin index was significantly lower [p = 0.0006, WMD = −0.12 (−0.19, −0.05)] in AIS girls than those of healthy control girls. The body mass index was significantly lower in AIS girls [p = 0.03, WMD = −1.53 (−2.95, −0.12) kg/m²]. The current meta-analysis showed that the level of sOB-R is higher in AIS patients than controls, while the concentration of leptin remains unchanged in AIS patients. Further well-designed studies would be necessary to substantiate our results.     

Physical activity and restlessness correlate with leptin levels in patients with adolescent anorexia nervosa.

BACKGROUND: In food-restricted rats, leptin suppresses semistarvation-induced hyperactivity (SIH) and decreases exploratory behavior. Leptin ameliorates anxiety-related movement in ob/ob mice. In this study, we assessed the relationship between leptin and qualities of physical activity and restlessness in acute anorexia nervosa (AN). METHODS: Serum leptin, body mass index (BMI), % body fat, and self- and expert-ratings of qualities of physical activity and restlessness were assessed in 26 inpatients with acute AN. Accelerometry was also performed. Regression analyses were used to predict activity and restlessness using BMI, % body fat, and leptin levels as predictor variables. RESULTS: Leptin levels significantly contributed to the prediction of all measures of activity and restlessness. CONCLUSIONS: This is the first study linking hypoleptinemia in AN patients to subjective and objective measures of higher physical activity and motor and inner restlessness. Leptin may directly or indirectly (or both) influence behaviors and cognitions contributing to hyperactivity and motor restlessness.     

Chronic antiepileptic monotherapy,bone metabolism,and body composition in non‐institutionalized children

Aim The aim of this study was to determine the influence of chronic monotherapy with antiepileptic drugs (AEDs) on vitamin D levels, bone metabolism, and body composition. Method Eighty‐five children (38 males, 47 females; mean age 12y 5mo, SD 3y 4mo) were treated with valproate and 40 children (28 males, 12 females; mean age 11y 10mo, SD 3y) were treated with other AEDs (lamotrigine, sulthiame, or oxcarbazepine), comprising the non‐valproate group. Forty‐one healthy children (29 males 12 females; mean age 12y 1mo, SD 3y 5mo) served as a comparison group. Height, weight, body impedance analysis, 25‐hydroxyvitamin D, calcium, phosphate, two bone resorption markers (receptor activator of nuclear factor κB ligand [RANKL] and tartrate‐resistant acid phosphatase 5b [TRAP5b]), osteoprotegerin, and leptin were measured. Results No child was vitamin D deficient as defined by a 25‐hydroxyvitamin D (25OHD) level of less than 25nmol/l (<10ng/ml). Leptin, body fat, weight standard deviation score (SDS), and body mass index (BMI) SDS were all significantly higher (each p<0.001) in valproate‐treated children than in the non‐valproate group, as were calcium (p=0.027) and RANKL (p=0.007) concentrations. Similarly, leptin was significantly higher in the valproate group than in control participants (p<0.001), as were body fat (p=0.023), weight SDS (p=0.046), BMI SDS (p=0.047), calcium (p<0.001), and RANKL (p<0.001), whereas TRAP5b concentrations were significantly lower in the valproate‐treated group (p=0.002). Furthermore, calcium and RANKL levels were significantly higher in the non‐valproate group than in comparison participants (p<0.001 and p=0.016 respectively). Interpretation Non‐enzyme‐inducing or minimal enzyme‐inducing AED monotherapy does not cause vitamin D deficiency in otherwise healthy children with epilepsy. Valproate therapy is associated with increases in weight, body fat, and leptin concentration, as well as with a bone metabolic profile that resembles slightly increased parathyroid hormone action.     

Interactions between the stimulated hypothalamic-pituitary-adrenal axis and leptin in humans

Leptin, produced by adipocytes, has homeostatic effects on body fat mass through inhibition of appetite and stimulation of the sympathetic nervous system. Several studies have reported that high-dose exogenous glucocorticoids increase circulating leptin concentrations in humans. Conversely, leptin has inhibitory effects on the hypothalamic-pituitary-adrenal (HPA) axis, both at the hypothalamic and adrenal levels. We hypothesized that acute hypercortisolism, in the physiological range, may not alter leptin secretion. Four stimuli of the HPA axis were administered to eight healthy male volunteers in a placebo-controlled study. On separate afternoons, in a randomised order, fasting subjects received i.v. injections of saline, naloxone (125 microg/kg); vasopressin (0.0143 IU/kg); naloxone and vasopressin in combination; or insulin (0.15 U/kg; a dose sufficient to induce hypoglycaemia). Plasma concentrations of adrenocorticotrophic hormone (ACTH), cortisol and leptin were measured before and for 120 min after the injection. The cortisol secretory response was greatest after insulin-hypoglycaemia, this response was significantly greater than that following naloxone, naloxone/vasopressin, or vasopressin alone. Despite the cortisol release, leptin concentrations were not increased after any stimulus. Insulin-hypoglycaemia was associated with a decrease in leptin concentration at 60 and 90 min, while naloxone did not alter leptin concentrations. However, basal leptin concentrations were positively correlated with integrated ACTH and cortisol responses to naloxone, but did not correlate with ACTH or cortisol responses to the other stimuli. Thus acute elevations of plasma cortisol, in the physiological range, do not appear to influence plasma leptin concentrations. The fall in plasma leptin concentration after insulin-induced hypoglycaemia may reflect catecholamine secretion after this stimulus.     

Hormone profiles in young adults with epilepsy treated with sodium valproate or lamotrigine monotherapy

PURPOSE: Treatment with sodium valproate (VPA) may be associated with polycystic ovarian syndrome (PCOS) in some women with epilepsy. By comparing hormone profiles in young adults taking VPA or lamotrigine (LTG) as monotherapy, this study aimed to explore whether a pharmacologic effect of VPA could be responsible for this observation. METHODS: Hormone profiles in men and women taking VPA (n = 40) or LTG (n = 36) monotherapy for epilepsy were compared. None of the women were receiving hormonal contraception or replacement. Patients gave details of seizure type and frequency, menstrual cycle, and medical and drug history. Body mass index was calculated, and fasting insulin, glucose, cholesterol, triglycerides (TG), high- and low-density lipoproteins, testosterone, dihydroepiandosterone (DHEA), androstenedione, sex hormone-binding globulin (SHBG), free androgen index (FAI), luteinising hormone (LH), follicle-stimulating hormone (FSH), and antiepileptic drug (AED) concentrations were measured. RESULTS: There were no differences between treatment groups for both sexes in age and seizure control. Only four obese VPA-treated women were hyperinsulinaemic (p = 0.05); three with abnormal menstrual cycles; one with raised testosterone. Testosterone (p = 0.02), FAI (p = 0.03), and TG (p = 0.02) levels were higher, however, in women taking the drug. Obese patients of both sexes (p = 0.01) and VPA-treated men (p = 0.03) had higher insulin concentrations. CONCLUSIONS: VPA therapy may be associated with subclinical elevation in fasting insulin levels. Testosterone and TG levels were higher in VPA-treated women compared with the levels in those taking LTG. However, only a minority of obese females exhibited biochemical characteristics suggestive of PCOS. Biochemical screening may allow women at risk of developing PCOS to avoid VPA.     

Resistance to the satiety action of leptin following chronic central leptin infusion is associated with the development of leptin resistance in neuropeptide Y neurones

Leptin regulates food intake and body weight by acting primarily in the hypothalamus. In humans and rodents, obesity is associated with hyperleptinaemia, suggesting a possible state of leptin resistance. Thus, to begin to examine the mechanisms of leptin resistance, we developed a rat model in which chronic central leptin infusion results in the development of resistance to leptin's satiety action. Adult male rats were infused chronically into the lateral cerebroventricle with leptin (160 ng/h) or phosphate-buffered saline via Alzet pumps for 28 days, followed by artificial cerebrospinal fluid infusion for 3 weeks. After the initial decrease in food intake, rats developed resistance to the satiety action of leptin, and withdrawal of the chronic leptin infusion resulted in hyperphagia. During leptin infusion, body weight was gradually decreased to reach a nadir on day 12, and thereafter, body weight was sustained at a reduced level throughout the entire 28-day infusion, despite normalization in food intake. Body weight was mostly normalized by day 22 postleptin. Since neuropeptide Y (NPY) neurones are one of the targets of leptin signalling in the hypothalamus, we next examined whether the development of resistance to the satiety action of leptin was due to altered NPY gene expression. On day 3-4 of infusion, hypothalamic NPY mRNA levels, as determined by RNAse protection assay (RPA), were significantly decreased in leptin treated rats compared to controls. By contrast, on day 16 of infusion, NPY mRNA levels in the leptin treated group had returned to control levels. In situ hybridization study confirmed the results obtained with RPA and showed further that the effect of chronic leptin infusion on NPY mRNA levels was restricted to the rostral and middle parts of the arcuate nucleus. Overall, the finding that the action of continuous leptin exposure on NPY neurones was not sustained suggests that NPY neurones may be involved in the development of leptin resistance to the satiety action of leptin in the hypothalamus.     

Nutritional regulation of hypothalamic leptin receptor gene expression is defective in diet-induced obesity

Leptin action in the hypothalamus plays a critical role in maintaining normal food intake and body weight. Hyperleptinaemia is associated with obesity in humans and animal models, suggesting a state of leptin resistance. Although the mechanism of leptin resistance is not clearly understood, alterations in leptin receptor (Ob-R) gene expression have been proposed as a potential mechanism mediating modifications in leptin action in obesity and during changes in nutritional status (fed/fasted). The current study examined the effects of diet-induced obesity (DIO) made by feeding rats a high fat diet for 9 weeks, and nutritional status on levels of long form (Ob-Rb) and total (Ob-Rtot) Ob-R mRNA expression in the hypothalamus. In the fed state, hypothalamic Ob-Rb mRNA and Ob-Rtot mRNA levels were similar in DIO and control standard chow fed rats (SC) despite hyperleptinaemia in DIO rats. However, although an overnight fast moderately increased hypothalamic Ob-Rb mRNA levels in SC rats, fasting did not increase Ob-Rb mRNA levels in DIO rats. To address the possibility that elevated leptin concentration in DIO rats may mediate an alteration in OB-R mRNA levels, we examined the effects of adenovirus-mediated hyperleptinaemia on Ob-R gene expression in SC rats. Despite substantially elevated plasma and cerebrospinal fluid concentrations of leptin, hypothalamic Ob-R mRNA levels were similar in both groups. In conclusion, the current study demonstrates that DIO is associated with a loss of nutritional regulation of hypothalamic Ob-R mRNA levels, and that hyperleptinaemia is not sufficient to alter Ob-R mRNA expression.     

Increased cardiovascular risk markers in obesity are associated with body adiposity: role of leptin

Epidemiological studies have shown that obesity is associated with increased blood concentrations of proinflammatory factors and markers of endothelial dysfunction such as fibrinogen, C-reactive protein (CRP), and von Willebrand factor (vWF). We analyzed the association of these markers with percentage of body fat (BF), and the influence of leptin in a cross-sectional study of 1,089 subjects (366 men) aged 44 (34-53) [median (interquartile range)] years, who were classified as obese or nonobese according to BF estimated by whole-body air displacement plethysmography. Obesity was defined as BF >or= 25% in men and >or= 35% in women. Compared with non-obese subjects (mean +/- SD), obese patients had higher concentrations of fibrinogen (312 +/- 78 vs. 342 +/- 81 mg/dl, P < 0.001), CRP (0.41 +/- 0.75 vs. 0.75 +/- 1.04 mg/l, P = 0.014), vWF (107 +/- 29 vs. 123 +/- 55%, P < 0.001), and leptin (10.4 +/- 6.5 vs. 37.5 +/- 26.1 ng/ml, P < 0.0001). A positive correlation was observed between BF and fibrinogen (r = 0.266; P < 0.0001), logCRP (r = 0.409; P < 0.0001), and vWF (r = 206; P < 0.0001). Leptin was correlated with fibrinogen (r = 0.219, P < 0.0001), logCRP (r = 0., P < 0.0001), and vWF (r = 0.124, P = 0.002), but the statistical significance was lost after including BF in adjusted-correlation and multivariate analysis, suggesting that they are not regulated by leptin per se. In conclusion, the obesity-associated increase in the circulating concentrations of fibrinogen, CRP, and vWF is highly associated to BF and apparently not determined by leptin.     

Diet- and valproate-induced transient hyperammonemia: effect of l-carnitine

Hyperammonemia is an adverse effect of valproate (VPA) treatment. In particular, transient hyperammonemia has been reported to occur in VPA-treated patients after protein-rich meals. This phenomenon may occur secondary to a VPA-mediated carnitine insufficiency. We sought to confirm that protein ingestion would result in transient hyperammonemia and to determine whether supplementation with -carnitine would prevent this effect. We studied the effect of consumption of a standardized protein-rich meal (45 g protein) before (phase I) and after (phase II) administration of -carnitine 50 mg/kg/day for 7 days in 11 epileptic children (13.3 ± 2.3 years of age) receiving VPA. Venous blood was obtained during fasting (baseline) and at 2 and 4 hours after the protein-rich meal for analysis of ammonia (NH₃), and VPA concentrations. Mean VPA trough concentrations did not differ significantly at any time. After protein ingestion, 2-hour NH₃ concentration increase by 86% (P < .05) from baseline in phase I as compared with a 38% increase in phase II. In both phases I and II, 4-hour NH₃ concentrations decreased toward baseline values. We conclude that (1) modest protein ingestion can result in significant transient increases in NH₃ in VPA-treated children, (2) significant increases may occur in patients with normal fasting NH₃ concentrations, (3) these increases can be significantly attenuated by -carnitine supplementation, and (4) these changes do not appear to be related to changes in VPA concentration.     

Plasma leptin, neuropeptide Y, ghrelin, and adiponectin levels and carotid artery intima media thickness in epileptic children treated with valproate

Background

Weight gain is a common side effect of valproate (VPA) treatment, although the mechanism is not clear. Abnormal weight gain and obesity are associated with dyslipidemia, hypertension, and atherosclerosis. Measurement of the common carotid artery intima media thickness (CAIMT) gives a picture of early arterial wall alterations and, currently, is considered a noninvasive marker of premature atherosclerosis. The aim of the present study was to evaluate plasma insulin, leptin, neuropeptide Y (NPY), ghrelin, and adiponectin levels in children with epilepsy treated with VPA and to evaluate these parameters for early atherosclerosis.

Material and methods

Twenty prepubertal children with idiopathic epilepsy treated with VPA were enrolled in this study. Body mass index (BMI) and fasting insulin glucose ratio (FIGR) were calculated, and the plasma insulin, leptin, NPY, ghrelin, and adiponectin levels; the lipid profiles; and CAIMT were measured for all subjects before the treatment and after a follow-up period of 6 and 12?months.

Results

When pretreatment values were compared with those at the end of 6 and 12?months, the mean BMI values, plasma insulin, leptin, NPY levels, and FIGR were increased, whereas the plasma ghrelin and adiponectin levels, lipid profiles, and CAIMT did not change significantly at the end of 6 and 12?months.

Conclusion

These results suggest that weight gain during VPA treatment may be related to increases in insulin, leptin, and NPY levels. Additionally, in this study, no increase in the risk for early atherosclerosis was determined by CAIMT in children with epilepsy treated with VPA.