Therapy insight: neurological complications of prediabetes

Stroke and peripheral neuropathy are recognized neurological complications of diabetes. Increasing epidemiological evidence also implicates the prediabetic state of impaired glucose tolerance (IGT) as a risk factor for cerebrovascular events and peripheral neuropathy. Data linking IGT to cognitive decline or deficits, however, are less robust. IGT is one component of metabolic syndrome, together with central obesity, hypertension, hypertriglyceridemia and reduced HDL. Each component of metabolic syndrome is an independent risk factor for stroke, but hyperglycemia might be more important than other components in the pathogenesis of neuropathy. Goal-driven diet and exercise regimens, together with pharmacological treatment of hyperlipidemia and hypertension, reduce stroke risk, but the effect of these interventions on neuropathy has not been fully explored.     

Impaired glucose tolerance and metabolic syndrome in idiopathic neuropathy

Idiopathic neuropathy is one of the most common clinical problems encountered in general medical and neurological practices, accounting for up to 40% of all neuropathies in referral series. Several groups have reported an elevated prevalence of impaired glucose tolerance (IGT) in idiopathic neuropathy subjects, although the only carefully conducted case-control study suggested hypertriglyceridemia was a more important risk factor. The nature of the relationship between IGT and neuropathy is a subject of active debate. An evolving literature suggests metabolic syndrome, particularly dyslipidemia and obesity, are potent neuropathy risk factors for both idiopathic and diabetic neuropathy patients. Once established, diabetic neuropathy is likely to be very difficult to reverse. IGT-associated neuropathy, however, may be more amenable to therapy and could represent an ideal population in which to examine potential therapies for diabetes and obesity related neuropathies. Further research is needed to better define the epidemiological relation between IGT, metabolic syndrome, and neuropathy, its underlying pathophysiology, and to develop appropriate surrogate measures and clinical trials strategies.     

急性缺血性卒中患者颅内动脉粥样硬化性狭窄与不同血糖水平代谢综合征的相关性分析

目的 探讨急性缺血性卒中患者颅内动脉粥样硬化性狭窄与不同血糖水平代谢综合征的相关性。 方法 选取2013年6月-2016年6月入住本院神经内科的急性缺血性卒中患者352例为研究对象,根 据颅内血管狭窄情况分为狭窄组227例和非狭窄组125例;选取同期非颅内动脉粥样硬化性狭窄体检 者310例为对照组。研究对象中合并代谢综合征的患者分为3个亚组：糖耐量正常组、伴糖尿病组、伴 高血糖组（包括空腹血糖受损、糖耐量降低）。同时测定代谢综合征患者血脂水平,分析不同血糖 水平代谢综合征与颅内动脉粥样硬化性狭窄的相关性。 结果 352例急性缺血性卒中患者共确诊代谢综合征195例（55.39%）,其中狭窄组和非狭窄组代谢 综合征的发生率均明显高于对照组,比较差异有显著性（P <0.05）;狭窄组代谢综合征的发生率明显 高于非狭窄组,比较差异有显著性（P <0.05）。狭窄组中伴糖尿病的代谢综合征患者比例明显高于非 狭窄组和对照组,比较差异有显著性（P <0.05）;狭窄组中伴高血糖和糖耐量正常的代谢综合征患 者比例与非狭窄组比较,差异均无显著性（P＞0.05）。Logistic回归分析显示：代谢综合征与颅内动脉 粥样硬化性狭窄存在明显相关性;代谢综合征伴糖尿病、伴低高密度脂蛋白（high density lipoprotein, HDL）、高甘油三酯（triglyceride,TG）与颅内动脉粥样硬化性狭窄发生风险呈明显正相关。 结论 在急性缺血性卒中患者中,代谢综合征尤其是糖尿病、高TG血症及低HDL血症和颅内动脉粥 样硬化性狭窄密切相关。     

中间高血糖与急性脑血管病的关系

目的 探讨中间高血糖与急性脑血管病的关系.方法 以365例急性脑血管病住院患者为研究对象,检测其空腹血糖、随机血糖和血脂.非糖尿病患者于发病一周后进行葡萄糖耐量试验(OGTT).按糖代谢状况分为正常糖耐量组、中间高血糖组[包括空腹血糖受损(IFG),糖耐量受损(IGT),IFG合并IGT]及糖尿病组三组,比较各组间动脉粥样硬化危险因素发生率、疾病严重程度及B超发现颈动脉粥样硬化的差异.结果 本组资料中IFG、IGT及IFG合并lGT的发生率分别为1.37%、24.66%和3.01%.糖尿病组与正常糖耐量组高血压发病率差异有统计学意义(P=0.007),而正常糖耐量组与中间高血糖组、糖尿病组与中间高血糖组比较,高血压发病率差异无统计学意义(P>0.05).各组间吸烟率、饮酒率、血脂异常率、疾病严重程度及B超发现动脉粥样硬化率差异无统计学意义(P>0.05).结论 中间高血糖是急性脑血管病患者普遍存在的问题,其与动脉粥样硬化其他危险因索共同作用导致发病.     

Unfairness and the social gradient of metabolic syndrome in the Whitehall II Study

OBJECTIVES: Little work has investigated the relationship between unfairness and risk factors for heart disease. We examine the role of unfairness in predicting the metabolic syndrome and explaining the social gradient of the metabolic syndrome. METHODS: The design is a prospective study with an average follow-up of 5.8 years. Participants were 4128 males and 1715 females of 20 civil service departments in London (Whitehall II study). Sociodemographics, unfairness, employment grade, behavioral risk factors, and other psychosocial factors were measured at baseline (Phase 3, 1991-1993). Waist circumference, triglycerides, high-density lipoprotein (HDL) cholesterol, fasting glucose, and hypertension were used to define metabolic syndrome at follow-up (Phase 5, 1997-2000), according to the National Cholesterol Education Program/Adult Treatment Panel III guidelines. RESULTS: Unfairness is positively associated with waist circumference, hypertension, triglycerides, and fasting glucose and negatively associated with serum HDL cholesterol. High levels of unfairness are also associated with the metabolic syndrome [odds ratio (OR)=1.72, 95% CI=1.31-2.25], after adjustment for age and gender. After additional adjustment for employment grade, behavioral risk factors, and other psychosocial factors, the relationship between high unfairness and metabolic syndrome weakened but remained significant (OR=1.37, 95% CI=1.00-1.93). When adjusting for unfairness, the social gradient of metabolic syndrome was reduced by approximately 10%. CONCLUSION: Unfairness may be a risk factor for the metabolic syndrome and its components. Future research is needed to study the biological mechanisms linking unfairness and the metabolic syndrome.     

Does antipsychotic polypharmacy increase the risk for metabolic syndrome?

OBJECTIVE: To determine whether the coprescribing of two or more antipsychotics, a relatively frequent practice with little data to support its safety and efficacy, is associated with an increased prevalence of metabolic syndrome. METHODS: 364 newly admitted adults treated with second-generation antipsychotics underwent assessments evaluating antipsychotic polytherapy, and of the presence of metabolic syndrome and triglycerides/high-density lipoprotein cholesterol ratio>3.5 (TG/HDL), a sensitive marker of insulin resistance. The correlates of antipsychotic polytherapy and associations with metabolic syndrome and TG/HDL were determined by univariate comparisons and multiple logistic regression analyses. RESULTS: Antipsychotic polytherapy was present in 70 patients (19.2%) and was significantly more likely in patients with schizophrenia and those treated with clozapine, quetiapine or ziprasidone (p<0.0001). Compared with antipsychotic monotherapy, polytherapy was associated with elevated rates of metabolic syndrome (50.0% vs. 34.3%, p=0.015) and TG/HDL (50.7% vs. 35.0%, p=0.016). However, in logistic regression analyses, metabolic syndrome was significantly associated with higher body mass index (BMI), older age, a diagnosis of bipolar disorder or schizophrenia, and cotreatment with a first-generation antipsychotic (r(2): 0.25, p<0.0001). The TG/HDL marker of insulin resistance was associated with higher BMI, male sex, Caucasian race and absence of aripiprazole treatment (r(2): 0.14, p<0.0001). Antipsychotic polypharmacy dropped out of both multivariate models. CONCLUSIONS: Compared with patients receiving antipsychotic monotherapy, patients on antipsychotic polytherapy have higher rates of metabolic syndrome and lipid markers of insulin resistance. However, antipsychotic polytherapy is not independently associated with the prevalence of these abnormalities, which are related to known demographic, clinical and anthropometric risk factors.     

Change in metabolic syndrome parameters with antipsychotic treatment in the CATIE Schizophrenia Trial: prospective data from phase 1

BACKGROUND: The metabolic syndrome (MS) is associated with increased risk for diabetes mellitus and coronary heart disease, and is highly prevalent among schizophrenia patients. Given concerns over antipsychotic metabolic effects, this analysis explored MS status and outcomes in phase 1 of the CATIE Schizophrenia Trial. METHODS: The change in proportion of subjects with MS and individual criteria was compared between antipsychotic treatment groups, along with mean changes for individual criteria. Primary analyses examined subjects with fasting laboratory assessments at baseline and 3 months. Other analyses examined 3-month changes in MS status, waist circumference (WC), HDL cholesterol and blood pressure in all subjects, metabolic changes at the end of phase 1 participation (EOP), and repeated measures changes in HDL, blood pressure (BP) and WC over phase 1. RESULTS: At 3 months, there were no significant between-drug differences for the change in proportion of subjects meeting MS status or individual MS criteria in the smaller fasting cohort (n = 281) or for those meeting criteria for parameters not dependent on fasting status (BP, HDL, WC) among all subjects (n=660). Among all subjects whose MS status could be determined at 3 months (n=660), MS prevalence increased for olanzapine (from 34.8% to 43.9%), but decreased for ziprasidone (from 37.7% to 29.9%) (p=.001). Although effect sizes varied across subgroups, at 3 months olanzapine and quetiapine had the largest mean increase in waist circumference (0.7 in. for both) followed by risperidone (0.4 in.), compared to no change for ziprasidone (0.0 in.) and a decrease in waist circumference for perphenazine (-0.4 in.). Olanzapine also demonstrated significantly different changes in fasting triglycerides at 3 months (+21.5 mg/dl) compared to ziprasidone (-32.1 mg/dl). EOP exposure data was obtained, on average, nine months from baseline for all metabolic variables. Results from EOP and repeated measures analyses were consistent with those at 3 months for mean changes in WC and fasting triglycerides, but between group differences emerged for HDL and SBP. CONCLUSIONS: This large non-industry sponsored study confirms the differential metabolic effects between antipsychotics. Clinicians are advised to monitor all metabolic parameters, including WC, HDL and serum triglycerides, during antipsychotic treatment.     

长寿老人心脑血管病相关危险因子及卒中患病的调查

目的探讨广西巴马长寿地区长寿老人心脑血管病相关危险因子及卒中患病情况。方法对巴马长寿地区≥90岁的长寿老人212例(长寿老人组)系统调查,并以非长寿地区老人222例(对照组)为对照,测量血压、血糖、血脂、体重指数水平及调查脑卒中患病情况。结果巴马长寿老人和对照组老人对比除舒张压、TG和LDL外,收缩压和TC、HDL水平高于普通老人,身高、体重、腰围、BMI和血糖水平低于对照组。长寿老人心脑血管相关危险因子患病粗率依次为高血压、高胆固醇血症、高甘油三酯血症、高血糖、高低密度脂蛋白血症和低高密度脂蛋白血症,而超重、腹型肥胖和肥胖患病粗率非常低。与对照组比较,高TC血症和高TG血症明显高于对照组(P<0.01);超重、肥胖、腹型肥胖和低HDL血症明显低于对照组(P<0.05)。长寿老人脑卒中患病粗率为2.36%。高血压是长寿老人卒中患病最常见危险因子。结论巴马长寿地区长寿老人心脑血管病的相关危险因子患病有其特异性,长寿老人较高的高血压、高血糖、高TC血症患病率及其低HDL血症、低体重、高HDL水平等代谢异常,可能构成了长寿的生化代谢基础。脑卒中患病粗率较低,早期预防和干预高血压有助于减少脑血管疾病发病危险。     

Restless legs syndrome in diabetic neuropathy: a frequent manifestation of small fiber neuropathy

As the occurrence of restless legs syndrome (RLS) in diabetes is controversial, the aim of this study was to assess the prevalence of RLS in a cohort of patients with diabetic neuropathy and to analyze the features of the associated neuropathy. We investigated the occurrence of RLS diagnosed in accordance with the criteria of the International Restless Legs Syndrome Study Group in a cohort of patients with polyneuropathy and mononeuropathy multiplex associated with diabetes mellitus (DM), or impaired glucose tolerance (IGT), or impaired fasting glucose (IFG) in a retrospective study. RLS was present in 33/99 patients with neuropathy associated with DM/IGT/IFG (84 with distal polyneuropathy and 15 with multiple mononeuropathy). Comparing patients with or without RLS, small fiber sensory neuropathy was more common in the RLS patients (15/33 vs. 15/66), as were symptoms of burning feet (10/33 vs. 6/66). In several patients, RLS was responsive to neuropathic pain medications. The frequent occurrence of RLS in association with thermal dysesthesias may reflect the involvement of small sensory fibers in the form of hyperexcitable C fibers or A-delta fiber deafferentation. We suggest that RLS may be triggered by abnormal sensory inputs from small fibers, especially involved in neuropathy associated with DM/IGT/IFG. Our data show that RLS is a relevant feature of diabetic neuropathy, as a frequent and potentially treatable manifestation of small fiber involvement in the course of DM and IGT/IFG.     

Prevalence of the metabolic syndrome among patients receiving clozapine

OBJECTIVE: This study compared the prevalence of the metabolic syndrome among outpatients with schizophrenia and schizoaffective disorder receiving clozapine with a matched comparison group from the National Health and Nutrition Examination Survey. METHOD: Ninety-three outpatients and a matched group of 2,701 comparison subjects were compared according to National Cholesterol Education Program criteria. Outpatient data were obtained through physical assessments, laboratory testing, and reviews of medical records. RESULTS: The prevalence of the metabolic syndrome was significantly higher among clozapine patients (53.8%) than among the comparison group (20.7%). For clozapine patients, logistic regression analysis revealed significant associations with age, body mass index, and duration of clozapine treatment. Only age and body mass index were associated with the prevalence of metabolic syndrome in both groups. CONCLUSIONS: Patients receiving clozapine are at significantly increased risk for developing the metabolic syndrome. Psychiatrists and other providers should consider performing regular physical health monitoring to prevent long-term adverse health consequences.     

Hypertension and sensorimotor peripheral neuropathy in type 2 diabetes

BACKGROUND: The mechanisms responsible for the onset of sensorimotor peripheral diabetic neuropathy (SMPN) remain largely unknown. To address this issue, we studied the relationship between traditional cardiovascular risk factors, parameters of metabolic control, and the presence of SMPN in patients with type 2 diabetes of relatively short duration. METHODS: Blood pressure, glycated hemoglobin, lipid profile, and the presence of micro- and macrovascular complications were assessed and monitored in 31 consecutive ambulatory patients with type 2 diabetes (age 60.7 +/- 7.5 years, mean +/- SD) within 10 years of diagnosis (mean diabetes duration 6.0 +/- 2.3 years). RESULTS: Clinical and neurophysiological features of SMPN were present in 10 patients (SMPN+, 32%). There were no significant differences in age, gender distribution, diabetes duration, body mass index, metabolic control, and serum cholesterol between SMPN- and SMPN+ patients. However, the prevalence of hypertension (i.e. blood pressure >/=140/90 mm Hg) was higher in SMPN+ patients (10/10 vs. 13/21, chi(2 =) 5.13, p = 0.025). Regression analysis showed that, after correcting for age, gender, duration of diabetes, glycated hemoglobin, and cholesterol, the presence of hypertension was independently associated with SMPN (R(2) = 0.17, p = 0.023). CONCLUSIONS: There is a strong association between hypertension and SMPN in type 2 diabetic patients with relatively short duration of disease. This relationship is independent of other risk factors.     

Prevalence of the metabolic syndrome in unipolar major depression

Previous studies on the association between affective disorders and the metabolic syndrome yielded inconclusive results. Therefore, we examined the prevalence of the metabolic syndrome in 230 men and women with unipolar major depressive disorder during inpatient treatment and compared it to 1,673 subjects from primary care from a similar region in northern Germany. We used the AHA/NHBLI criteria to determine the rate of metabolic syndrome (MetS) and each single criterion of MetS in both groups. The age-standardized prevalence of MetS was 2.4× as high in patients with major depressive disorder (MDD) compared with data from comparison subjects (41.0% vs. 17.0%). With respect to the single criteria, elevations were found in MDD patients for fasting glucose and triglycerides in both genders, and waist circumference in women. Men in the patient and the comparison groups were found to have higher rates of increased fasting glucose and triglycerides than women in the respective groups. Factors associated with the MetS in MDD patients comprise body mass index and the severity of depression. Our results demonstrate an increased prevalence of the MetS in men and women with MDD. Interventions for the frequently untreated metabolic abnormalities and careful screening for physical health conditions among people with MDD are warranted.     

Conference report: Belgian consensus on metabolic problems associated with atypical antipsychotics

BACKGROUND: The current literature supports that schizophrenia (and bipolar disorders) appear to be associated with a higher prevalence of type 2 diabetes. Because of the silent nature of diabetes mellitus, and the fact that schizophrenic patients are not screened comprehensively for the disease, the true prevalence of hyperglycemia and diabetes may be substantially underestimated. Notably, it has been suggested that schizophrenia as such carries an increased risk, as certain characteristics of schizophrenic patients such as unhealthy life style promote the diabetes risk. LITERATURE FINDINGS: This risk may be increased by antipsychotic drug treatment, as was already suggested for first-generation antipsychotics (FGA). The amount of literature on the association of SGA and metabolic disorders is much larger however, although well-controlled prospective data are sparse. Reports comprise abnormal glucose regulation, exacerbation of existing type 1 and 2 diabetes, new-onset pseudo-type 1 or type 2 diabetes, diabetic ketoacidosis, coma and death. In large-scale studies (mostly retrospective), reviews and meta-analyses, the association was not found for all drugs. NEW DATA: According to recent reviews, the risk of developing diabetes was highest for clozapine and olanzapine, followed by quetiapine and risperidone. The hierarchy of liability of weight gain, or differential effects on insulin resistance was also in the described order. Apart from disturbances in glucose metabolism, further frequent metabolic abnormalities in schizophrenic patients on SGA include features of the metabolic syndrome. Antipsychotics such as clozapine and olanzapine have also been associated with hypertriglyceridemia, while agents such as haloperidol, risperidone and ziprasidone were associated with reductions in plasma triglycerides. Amisulpride, aripiprazole and ziprasidone seem to carry the lowest risk for weight gain, diabetes and effects on insulin resistance. CONCLUSION: As a consequence, there is a shift in attention toward physical health monitoring in patients with mental health disorders. The APA and ADA as well a British working group have recently published the findings on SGA and metabolic abnormalities in a joint statement (table I).     

Metabolic syndrome in Italian patients with bipolar disorder

OBJECTIVE: This study aimed to evaluate the prevalence of metabolic syndrome (MetS) in Italian patients with bipolar disorder (BD) and to determine the sociodemographic and clinical correlates of MetS in this patient population. METHOD: Subjects with BD I and II were included. Sociodemographic and clinical characteristics, lifestyle information (alcohol and smoking habits and rate of physical exercise) and comorbidity for cardiovascular diseases and diabetes were collected. Patients were assessed for MetS according to both National Cholesterol Education Program Adult Treatment Panel III and International Diabetes Federation (IDF) criteria. RESULTS: MetS was evaluated in 99 patients out of 108 who were enrolled. MetS was present in 25.3% of the sample. Abdominal obesity was present in 50%, hypertension in 40%, high triglycerides in 34.7%, low HDL-C levels in 32.3% and fasting hyperglycemia in 11% of the sample. Prevalence of MetS was 30% when IDF criteria were employed. Of the investigated variables, age, duration of illness, rate of obesity and cardiovascular disease were higher in patients with MetS. After the regression analysis, only age and obesity were associated to MetS. CONCLUSIONS: MetS is highly prevalent in Italian patients with BD. Our 25.3% prevalence rate is consistent with the 21-22% reported in other European studies and lower than that in U.S. studies. Elderly and obese patients with BD are at particularly high risk for MetS.     

Metabolic syndrome and cognitive decline

Over 33% of women and 20% of men aged 65 and older will develop dementia during their lifetime, and many more will develop a milder form of cognitive impairment. Given the anticipated exponential increase in both the incidence and prevalence of cognitive impairment in the next century, it is critical to identify preventative strategies to thwart this critical public health issue. The metabolic syndrome is comprised of five cardiovascular risk factors that include abdominal obesity, hypertriglyceridemia, low high density lipoprotein (HDL) levels, hypertension, and hyperglycemia. The prevalence of the metabolic syndrome, similar to that for cognitive disorders, increases dramatically with age. While several of the individual components of the metabolic syndrome have been linked to risk of developing dementia and cognitive impairment, few studies have looked at the components of the metabolic syndrome as a whole. We found, in two separate studies involving elders of different ethnicities, that the metabolic syndrome is a risk factor for accelerated cognitive aging. This was especially true for elders with the metabolic syndrome and with elevated serum level of inflammation. Several possible mechanisms may explain the association between the metabolic syndrome and cognitive decline including micro- and macro-vascular disease, inflammation, adiposity and insulin resistance. If metabolic syndrome is associated with increased risk of developing cognitive impairment, regardless of mechanism, then early identification and treatment of these individuals might offer avenues for disease course modification.     

Hypertension-induced peripheral neuropathy and the combined effects of hypertension and diabetes on nerve structure and function in rats

Diabetic neuropathy includes damage to neurons, Schwann cells and blood vessels. Rodent models of diabetes do not adequately replicate all pathological features of diabetic neuropathy, particularly Schwann cell damage. We, therefore, tested the hypothesis that combining hypertension, a risk factor for neuropathy in diabetic patients, with insulin-deficient diabetes produces a more pertinent model of peripheral neuropathy. Behavioral, physiological and structural indices of neuropathy were measured for up to 6 months in spontaneously hypertensive and age-matched normotensive rats with or without concurrent streptozotocin-induced diabetes. Hypertensive rats developed nerve ischemia, thermal hyperalgesia, nerve conduction slowing and axonal atrophy. Thinly myelinated fibers with supernumerary Schwann cells indicative of cycles of demyelination and remyelination were also identified along with reduced nerve levels of myelin basic protein. Similar disorders were noted in streptozotocin-diabetic rats, except that thinly myelinated fibers were not observed and expression of myelin basic protein was normal. Superimposing diabetes on hypertension compounded disorders of nerve blood flow, conduction slowing and axonal atrophy and increased the incidence of thinly myelinated fibers. Rats with combined insulinopenia, hyperglycemia and hypertension provide a model for diabetic neuropathy that offers an opportunity to study mechanisms of Schwann cell pathology and suggests that hypertension may contribute to the etiology of diabetic neuropathy.     

Electrophysiologic severity of carpal tunnel syndrome in diabetic patients of the Saudi population

Objectives:To study the frequency of multiple vascular risk factors and electrophysiological severity of carpal tunnel syndrome (CTS) in Saudi diabetic patients.Methods:This retrospective cross-sectional study was conducted in Neurology Department, King Fahd Hospital of University, Al-Khobar, Kingdom of Saudi Arabia from April 2017 to March 2018 and included 200 patients with CTS. Body parameters, such as blood pressure (BP), weight, height, and body mass index (BMI), along with laboratory and median nerve electrophysiological parameters, of diabetic and non-diabetic patients were compared, and a p-value<0.05 was considered significant.Results:Frequency of hypertension (HTN) and obesity was significantly higher in diabetic patients (p<0.05). Mean median nerve sensory amplitude (MNSA) was lower in diabetic patients (p<0.05).Non-recordable nerves, as well as bilateral and extremely severe CTS (p<0.05), were more frequently seen in diabetic patients. Age, BMI, systolic BP, low serum high density lipoprotein (HDL), high triglycerides, high fasting blood sugar, and high glycated hemoglobin (Hba1c) levels, known to affect the electrophysiological severity of CTS, had a statistically significant association with diabetes.Conclusion:Diabetes mellitus (DM) and obesity are the most commonly identified risk factors of CTS. Dyslipidemia, HTN and obesity are more frequently seen in diabetic patients with CTS. These concurrent risk factors are confounding the electrophysiological severity of CTS in these patients. Further larger-scale studies with the control of confounding factors are recommended.

Carpal tunnel syndrome (CTS) is known to have a frequent nerve entrapment syndrome and encompasses 45% of non-traumatic nerve lesions.1,2 Carpal tunnel syndrome can result in various problems, including pain and paresthesia in the median nerve distribution, swelling, and in severe cases weakness of the thumb and lateral 3 fingers.3 It affects the daily life activities, such as holding and gripping things by hand, brushing teeth, and driving.4 Carpal tunnel syndrome can be associated with any risk factor that causes pressure on the median nerve inthe wrist, including coexisting comorbidities and working conditions of the individuals.5 Some common conditions that can lead to CTS includes obesity, DM, oral contraceptives, smoking, corticosteroid use, pregnancy, hypothyroidism, rheumatoid arthritis, osteoarthritis, and wrist fracture.6The prevalence of CTS in diabetic patients is 14% without diabetic neuropathy and 30% with diabetic neuropathy.7 Literature has shown a high incidence of CTS in pre-diabetic states.8 Some researchers have also found a relationship between duration of diabetes, Hba1c, and micro vascular complications.9 Although type 2 diabetes is more frequently diagnosed among CTS patients, some studies had reported that the association between diabetes and CTS represents a confusion bias, most likely due to the strong relationship between obesity and type 2 diabetes.10 It has been shown that age, BMI, and other vascular risk factors, including metabolic syndrome, could affect the electrophysiological severity of CTS. Elevated low density lipoprotein (LDL) cholesterol and hyperglycemia were reported as independent risk factors for CTS in some studies.8,11,12 Similarly, obesity, elevated triglycerides, elevated LDL cholesterol and hypertension were shown to be strongly associated with CTS.13 In the study conducted by Balci et al,14 75% of the CTS patients were found to have metabolic syndrome, and the electrophysiological parameters (median nerve sensory onset latency, sensory conduction velocity, sensory amplitude, distal motor latency, motor conduction velocity, and motor amplitude) were worse in patients with metabolic syndrome. Gül et al,15 similarly showed that severity of CTS was even more severe in patients with metabolic syndrome than in those with diabetes.The aim of the present study was to study the frequency of multiple vascular risk factors, such as HTN, dyslipidemia and obesity in CTS patients, and to compare the electrophysiological severity of CTS in Saudi diabetic and non diabetic patients. This population is facing a high burden of multiple vascular risk factors, which are also affecting the severity of CTS.     

Median-radial sensory nerve comparative studies in the detection of median neuropathy at the wrist in diabetic patients.

OBJECTIVE: Median-ulnar comparative studies (MUCS) play an important role in the electrodiagnosis of carpal tunnel syndrome, but in diabetes concomitant involvement of Guyon's canal (ulnar nerve compression at the wrist) would reduce the sensitivity of MUCS. This study tested the utility of median-radial comparative studies (MRCS) in diabetic patients. METHODS: Anti-dromic MUCS and MRCS were prospectively performed in 120 patients with diabetes, and 64 normal controls. In 28 diabetic patients, latent addition using threshold tracking was performed in superficial radial sensory axons to estimate persistent nodal sodium currents. RESULTS: MUCS was abnormal in 49% of the diabetic patients, and MRCS was abnormal in 58%. Median motor distal latencies were prolonged in 38%, and median sensory nerve conduction velocities were slowed in 40%. The longer latency differences in MRCS were associated with smaller persistent sodium currents, suggesting that intra-axonal sodium accumulation mediated by hyperglycemia enhances nerve compression. CONCLUSIONS: MRCS appears to be the most sensitive electrodiagnostic test in the detection of median neuropathy at the wrist in diabetic patients. Nerve conduction slowing across the carpal tunnel may be associated with metabolic abnormalities under hyperglycemia. SIGNIFICANCE: Assessment of nerve conduction across the common entrapment sites could provide new insights into the pathophysiology of diabetic neuropathy related to metabolic factors.     

The prevalence of the metabolic syndrome in patients with schizoaffective disorder--bipolar subtype

OBJECTIVES: To evaluate the point prevalence of the metabolic syndrome in patients with schizoaffective disorder--bipolar type. METHODS: Consenting patients who were participants in an ongoing clinical trial of adjunctive topiramate treatment for schizoaffective disorder, bipolar type were evaluated at baseline for the point prevalence of the metabolic syndrome. The criteria for the metabolic syndrome included: (a) waist circumference > 102 cm (40 inches) in males, or > 88 cm (35 inches) in females; (b) fasting serum triglyceride levels > or = 150 mg/dL; (c) fasting high density lipoproteins (HDL) cholesterol <40 mg/dL in men or <50 mg/dL in women; (d) blood pressure > or = 130/85 mmHg; and (e) fasting glucose > or = 110 mg/dL. Subjects who had at least three of these five criteria were defined as meeting criteria for the metabolic syndrome. RESULTS: Thirty-six subjects (males = 15, females = 21) were evaluated, and three were excluded for missing data. Among those 33 subjects with complete data, 14 subjects (42.4%, males = 7, females = 7, African Americans = 6, Caucasians = 8) met criteria for the metabolic syndrome. Not unexpectedly, those with the metabolic syndrome were significantly more likely to be obese, and have significantly higher mean systolic and diastolic blood pressure, mean fasting triglyceride levels and larger mean waist circumferences, and significantly lower HDL cholesterol levels; and a trend toward higher fasting blood glucose levels. Furthermore, the fasting mean total cholesterol in those with the metabolic syndrome was 217 mg/dL (+/-46). CONCLUSIONS: This preliminary report suggests that the point prevalence of the metabolic syndrome in patients with schizoaffective disorder appears to be higher than that reported in the general population of the USA. Targeted weight reduction and life style change strategies (increased exercise, smoking cessation, stress reduction) may provide useful interventions to decrease the morbidity and mortality that accompanies the presence of the metabolic syndrome in patients with psychiatric illnesses.