Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled Trial.

AIM: To investigate the effect of normalizing vitamin B12 (B12) levels with oral B12 (methylcobalamin) 1000 µg/day for one year in patients with diabetic neuropathy (DN). PATIENTS AND METHODS: In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin for at least four years and both peripheral and autonomic DN were randomized to an active treatment group (n = 44) receiving B12 and a control group (n = 46) receiving a placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurements of sural nerve conduction velocity (SNCV), sural nerve action potential (amplitude) (SNAP), and vibration perception threshold (VPT), and they performed cardiovascular autonomic reflex tests (CARTs: mean circular resultant (MCR), Valsalva test, postural index, and orthostatic hypotension). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet (ESCH and ESCF, respectively). We also used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively) and questionnaires to evaluate quality of life (QoL) and level of pain (pain score). RESULTS: B12 levels increased from 232.0 ± 71.8 at baseline to 776.7 ± 242.3 pmol/L at follow-up, p < 0.0001, in the active group but not in the control group. VPT, MNSIQ, QoL, pain score, SNCV, SNAP, and ESCF significantly improved in the active group (p < 0.001, p = 0.002, p < 0.0001, p < 0.000, p < 0.0001, p < 0.0001, and p = 0.014, respectively), whereas CARTS and MNSIE improved but not significantly. MCR, MNSIQ, SNCV, SNAP, and pain score significantly deteriorated in the control group (p = 0.025, p = 0.017, p = 0.045, p < 0.0001, and p < 0.0001, respectively). CONCLUSIONS: The treatment of patients with DN with 1 mg of oral methylcobalamin for twelve months increased plasma B12 levels and improved all neurophysiological parameters, sudomotor function, pain score, and QoL, but it did not improve CARTS and MNSIE.

An extended fatty liver index to predict non-alcoholic fatty liver disease.

BACKGROUND: In clinical practice, there is a strong interest in non-invasive markers of non-alcoholic fatty liver disease (NAFLD). Our hypothesis was that the fold-change in plasma triglycerides (TG) during a 2-h oral glucose tolerance test (fold-change TGOGTT) in concert with blood glucose and lipid parameters, and the rs738409 C>G single nucleotide polymorphism (SNP) in PNPLA3 might improve the power of the widely used fatty liver index (FLI) to predict NAFLD. METHODS: The liver fat content of 330 subjects was quantified by 1H-magnetic resonance spectroscopy. Blood parameters were measured during fasting and after a 2-h OGTT. A subgroup of 213 subjects underwent these measurements before and after 9 months of a lifestyle intervention. RESULTS: The fold-change TGOGTT was closely associated with liver fat content (r=0.51, P<0.0001), but had less power to predict NAFLD (AUROC=0.75) than the FLI (AUROC=0.79). Not only was the fold-change TGOGTT independently associated with liver fat content and NAFLD, but so also were the 2-h blood glucose level and rs738409 C>G SNP in PNPLA3. In fact, a novel index (extended FLI) generated from these and the usual FLI parameters considerably increased its power to predict NAFLD (AUROC=0.79-0.86). The extended FLI also increased the power to predict changes in liver fat content with a lifestyle intervention (n=213; standardized beta coefficient: 0.23-0.29). CONCLUSION: This study has provided novel data confirming that the OGTT-derived fold-change TGOGTT and 2-h glucose level, together with the rs738409 C>G SNP in PNPLA3, allow calculation of an extended FLI that considerably improves its power to predict NAFLD.

The effect of age on complications in women undergoing minimally invasive sacral colpopexy.

INTRODUCTION AND HYPOTHESIS: Previous research has demonstrated similar complication rates in older and younger women undergoing abdominal sacral colpopexy via laparotomy. The objective of this study was to compare perioperative complications in older and younger women undergoing minimally invasive sacral colpopexy. METHODS: This was a retrospective study of laparoscopic and robotic sacral colpopexies performed from January 2009 to May 2012 at a large academic center. Patient demographics, surgical data, and perioperative complications were compared in women < 65 and ≥65 years of age. Primary outcome was the difference in major complications. RESULTS: A total of 302 women underwent minimally invasive sacral colpopexy during the study period. Mean age was 58.5 ± 8.8 years and 84 subjects (27.8 %) were ≥65 years. Older women were more likely to have had a prior hysterectomy (60.7 vs 39.0 %, p = 0.001) and had more severe preoperative prolapse (86.9 % vs 71.9 % ≥ POPQ stage III, p = 0.01). There was no significant difference in duration of hospitalization (1.4 vs 1.4 days, p = 0.54). Overall, there were significantly more major complications in women ≥ 65 years (unadjusted OR 1.84, 95 % CI 1.02-3.35, p = 0.04). After controlling for BMI, route of surgery, estimated blood loss (EBL), and operating room time, age ≥ 65 remained a significant predictor of complications (adjusted OR 2.28, 95 % CI 1.21-4.29, p = 0.01). CONCLUSIONS: Our findings suggest that older women have a higher rate of major complications following minimally invasive sacral colpopexy, even after controlling for BMI, route of surgery, EBL, and operating room time. This increased risk should be addressed during preoperative counseling and may influence surgical planning.

Insulin resistant phenotype of polycystic ovary syndrome does not seem to be caused by variation in FTO.

Genetic variation in the FTO gene is associated with increased body weight and reduced insulin sensitivity. We investigated whether genetic variation in FTO is associated with polycystic ovary syndrome (PCOS), a condition also characterized by insulin resistance. Furthermore, we tested whether insulin resistance is specifically associated with genetic variation in FTO in women with PCOS. Sixty-two nondiabetic patients with PCOS defined by the Rotterdam criteria were compared to BMI and age-matched women. Each PCOS case was matched to 2 controls. All participants underwent an oral glucose tolerance test and were genotyped for the single nucleotide polymorphism rs8050136 in the FTO gene. There was no difference in the frequency of FTO genotypes between the PCOS and the non-PCOS groups. In non-PCOS participants, genetic variation in FTO is associated with insulin sensitivity (p=0.03). This association remained significant after adjustment for age and/or BMI (p<= 0.03). In subjects with PCOS, however, FTO did not associate with insulin sensitivity (p=0.67). Genetic variation in FTO does not have an impact on insulin sensitivity in women with PCOS and is therefore not involved in the pathogenesis of the insulin resistant phenotype seen in patients with PCOS.

Visceral obesity modulates the impact of apolipoprotein C3 gene variants on liver fat content.

OBJECTIVE: It has not been solved whether subjects carrying the minor alleles of the -455T>C or -482C>T single nucleotide polymorphisms (SNPs) in the apolipoprotein-C3-gene (APOC3) have an increased risk for developing fatty liver and insulin resistance. We investigated the relationships of the SNPs with hepatic APOC3 expression and hypothesized that visceral obesity may modulate the effects of these SNPs on liver fat and insulin sensitivity (IS). METHODS: APOC3 mRNA expression and triglyceride content were determined in liver biopsies from 50 subjects. In a separate group (N=330) liver fat was measured by (1)H-magnetic resonance spectroscopy. IS was estimated during an oral glucose tolerance test (OGTT) and the euglycemic, hyperinsulinemic clamp (N=222). RESULTS: APOC3 mRNA correlated positively with triglyceride content in liver biopsies (r=0.29, P=0.036). Carriers of the minor alleles (-455C and -482T) tended to have higher hepatic APOC3 mRNA expression (1.80 (0.45-3.56) vs 0.77 (0.40-1.64), P=0.09), but not higher triglyceride content (P=0.76). In 330 subjects the genotype did not correlate with liver fat (P=0.97) or IS (OGTT: P=0.41; clamp: P=0.99). However, a significant interaction of the genotype with waist circumference in determining liver fat was detected (P=0.02) in which minor allele carriers had higher liver fat only in the lowest tertile of waist circumference (P=0.01). In agreement, during a 9-month lifestyle intervention the minor allele carriers of the SNP -482C>T in the lowest tertile also had less decrease in liver fat (P=0.04). CONCLUSIONS: APOC3 mRNA expression is increased in fatty liver and is regulated by SNPs in APOC3. The impact of the APOC3 SNPs on fatty liver is small and depends on visceral obesity.

Type 2 diabetes mellitus and risk of malignancy: is there a strategy to identify a subphenotype of patients with increased susceptibility to endogenous and exogenous hyperinsulinism?

AIMS: To give an overview on the relationship between diabetes mellitus and increased cancer risk. METHODS: We identified studies evaluating the association between diabetes mellitus, its treatment with insulin and insulin analogues and malignancies, paying special attention to studies on in vitro and in vivo effects of the long-acting analogue insulin glargine. RESULTS: Even although the pathophysiological mechanisms underlying the relationship between elevated cancer risk and Type 2 diabetes mellitus are not completely understood, hyperinsulinaemia in the presence of insulin resistance appears to be a key factor. Because of the mitogenic actions of insulin at high concentrations, hyperinsulinaemia may favour tumorigenesis. In line with this, an insulin-based therapy is associated with an increased cancer risk, whereas an insulin-sensitizing treatment results in a cancer risk reduction. Furthermore, alterations of the insulin receptor profile on tumour cells may contribute to an enhanced susceptibility towards insulin. Studies on the analogue insulin glargine have been controversial. In vitro data pointed to an elevated mitogenicity of insulin glargine, whereas in vivo data did not confirm cancerogenous effects. Moreover, recently published clinical studies on the association of insulin glargine (Lantus®) and cancer suggest that treatment with insulin glargine is not associated with increased cancer risk. CONCLUSIONS: The relationship between elevated cancer risk and Type 2 diabetes mellitus has been shown by numerous epidemiological studies, with endogenous and exogenous hyperinsulinaemia in the presence of insulin resistance as potential underlying pathophysiological mechanisms. Recent clinical studies do not support an increased cancer risk in patients treated with insulin glargine.

Effects of a lifestyle intervention in metabolically benign and malign obesity.

AIMS/HYPOTHESIS: We and others recently characterised metabolically benign or healthy obesity (MHO). In the present study we investigated whether a lifestyle intervention is sufficient to place obese insulin-resistant (OIR) individuals in a position where the possible metabolic consequences are similar to those for MHO individuals. METHODS: A total of 262 non-diabetic individuals participated in a 9 month lifestyle intervention programme. Obese individuals (BMI ≥ 30.0 kg/m(2)) were stratified, based on their insulin sensitivity (IS) estimated from an OGTT, into MHO (IS in the upper quartile, n = 26) and OIR (IS in the lower three quartiles, n = 77). Total body and visceral fat were measured by magnetic resonance (MR) tomography and liver fat by (1)H-MR spectroscopy. RESULTS: During the intervention, visceral fat decreased significantly in both groups (both p ≤ 0.009), whereas total body and liver fat decreased only in the OIR group (p < 0.0001; MHO p = 0.12 for total body fat and p = 0.47 for liver fat). IS improved in the OIR group (p < 0.0001), but remained essentially unchanged in the MHO group (p = 0.30). However, despite the significant increase in the OIR group, IS at follow-up barely exceeded 50% of the IS of the MHO group (OIR 9.30 ± 0.53 arbitrary units [AU]; MHO 16.41 ± 1.05 AU; p < 0.0001). CONCLUSIONS/INTERPRETATION: IS improves during the lifestyle intervention in OIR individuals. However, it does not reach a level where adequate protection from type 2 diabetes and cardiovascular disease is expected. Thus, stratification of obese individuals based on their metabolic phenotype is important to identify those who are likely to need early pharmacological treatment in addition to the lifestyle intervention.

[Diabetes, insulin, insulin analogues, and cancer]. / Diabetes, Insulin, Insulinanaloga und Karzinome.

Numerous epidemiological studies have demonstrated an association between increased risk of cancer development and progression and type 2 diabetes mellitus as well as obesity. The underlying mechanisms remain elusive, but hyperinsulinaemia in the presence of insulin resistance appears to be an important factor. Hyperinsulinaemia may favour tumorigenesis, as insulin has not only metabolic actions, but is also mitogenic at high concentrations. Besides, susceptibility of tumour cells against insulin may be increased due to changes in the insulin receptor profile. A diabetes therapy with insulin or sulfonylureas, which leads to elevated exogenous or endogenous insulin levels, appears to be related with an increased cancer risk, whereas administration of metformin or thiazolidinediones, which is associated with a decrease of insulin concentrations, results in risk reduction. However, in light of the numerous epidemiological studies showing an association between increased cancer risk and reduced physical activity one cannot exclude that hyperinsulinaemia in the presence of insulin resistance is only a surrogate parameter of reduced physical activity. In the past years, several insulin analogues have been developed which may have altered mitogenic actions compared to human insulin due to their structural changes. For the long-acting analogue insulin glargine, in vitro data, though controversial, pointed to an increased mitogenicity that was, however, not confirmed by in vivo studies. Recently, six clinical studies have been published that analysed the association between the application of insulin glargine (Lantus) and cancer development. The current clinical data do not allow the conclusion that treatment with insulin glargine is associated with increased cancer risk. On the other hand, prospective studies that exclude an impact on cancer risk in risk populations are currently not available. Future studies are required to investigate whether a subpopulation characterised by a less rapid metabolization of insulin glargine in vivo may be at increased cancer risk. In the present article, we give an overview on the association between diabetes mellitus, its treatment with insulin analogues, and cancer.

The ENPP1 K121Q polymorphism determines individual susceptibility to the insulin-sensitising effect of lifestyle intervention.

AIMS/HYPOTHESIS: The K121Q (rs1044498) single nucleotide polymorphism (SNP) in the ENPP1 gene has shown association with insulin resistance and type 2 diabetes in various ethnic populations. We hypothesised that K121Q may predict the success of lifestyle intervention in terms of improvement of insulin sensitivity. METHODS: We genotyped 1,563 participants with an increased risk of type 2 diabetes for K121Q and performed correlational analyses with anthropometric data and variables of insulin sensitivity. For metabolic characterisation, all participants underwent an OGTT. A subgroup of 506 participants additionally underwent a euglycaemic-hyperinsulinaemic clamp. In 342 participants, metabolic traits and anthropometric data were re-evaluated after a 9 month lifestyle intervention. RESULTS: In the overall cohort, K121Q was not associated with measures of obesity, indices of glucose tolerance during OGTT and insulin sensitivity estimated from the OGTT or derived from a euglycaemic-hyperinsulinaemic clamp after appropriate adjustment. However, K121Q did significantly influence the change in insulin sensitivity during lifestyle intervention after appropriate adjustment (p (additive) = 0.0067, p (dominant) = 0.0027). Carriers of the minor allele had an impaired increase in OGTT-derived insulin sensitivity. A similar trend was obtained for clamp-derived insulin sensitivity, but did not reach significance. CONCLUSIONS/INTERPRETATION: In our population of European ancestry, the ENPP1 SNP K121Q influenced the change in insulin sensitivity during lifestyle intervention. Thus, this SNP may determine susceptibility to environmental changes and could predict the success of lifestyle intervention.

The impact of liver fat vs visceral fat in determining categories of prediabetes.

AIMS/HYPOTHESIS: Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are risk factors for type 2 diabetes and cardiovascular disease; however, their impact on these endpoints differs. Because liver fat and visceral fat are important determinants of glucose and lipid metabolism, we investigated whether these fat compartments and their humoral products, the adipokine adiponectin and the hepatokine fetuin-A, differ in their impact on the glucose categories. METHODS: In 330 individuals at risk of type 2 diabetes, glucose tolerance status was determined by a 2 h 75 g OGTT. Total-body and visceral fat were precisely quantified by magnetic resonance (MR) tomography and liver fat by (1)H-MR spectroscopy. RESULTS: A total of 210 individuals had normal glucose tolerance (NGT), 41 isolated IFG, 43 isolated IGT and 36 IFG+IGT. Total-body fat was not different (p = 0.51), although a small but continuous increase in visceral fat was found among the categories after adjustment for age and sex (NGT: 3.07 +/- 0.10 kg; IFG: 3.11 +/- 0.21 kg; IGT: 3.61 +/- 0.21 kg; IFG+IGT: 3.84 +/- 0.23 kg [SEs], p = 0.03). A larger difference was found for liver fat (NGT: 4.73 +/- 0.42%; IFG: 5.86 +/- 0.92%; IGT: 8.65 +/- 0.92%; IFG + IGT: 11.11 +/- 1.01%, p < 0.0001). The differences among the categories were small for adiponectin (p = 0.14), but larger for fetuin-A (p = 0.015). Among fat compartments, liver fat (p < 0.0001) and among circulating variables fetuin-A (p = 0.016) were the strongest determinants of the categories. CONCLUSIONS/INTERPRETATION: Liver fat, more than visceral fat, strongly increases when glycaemia and glucose tolerance move from NGT to isolated IFG, isolated IGT and IFG+IGT. Because liver-derived circulating fetuin-A determines, although weakly, prediabetes categories, it is worth searching for hepatokines more strongly predicting prediabetes.

High cardiorespiratory fitness is an independent predictor of the reduction in liver fat during a lifestyle intervention in non-alcoholic fatty liver disease.

OBJECTIVE: Lifestyle intervention with diet modification and increase in physical activity is effective for reducing hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD). However, for a similar weight loss, there is a large variability in the change in liver fat. We hypothesised that cardiorespiratory fitness may predict the response to the intervention. DESIGN: Longitudinal study with increase in physical activity and diet modification. SETTING: University teaching hospital. PATIENTS: 50 adults with NAFLD and 120 controls at risk for metabolic diseases. MAIN OUTCOME MEASURES: Total-, subcutaneous abdominal- and visceral adipose tissue by magnetic resonance tomography, liver fat by 1HMR spectroscopy and cardiorespiratory fitness (VO(2,max)) by a maximal cycle exercise test at baseline and after 9 months of follow-up. RESULTS: In all subjects total-, subcutaneous abdominal- and visceral adipose tissue decreased and fitness increased (all p<0.0001) during the intervention. The most pronounced changes were found for liver fat (-31%, p<0.0001). Among the parameters predicting the change in liver fat, fitness at baseline emerged as the strongest factor, independently of total- and visceral adipose tissue as well as exercise intensity (p = 0.005). In the group of subjects with NAFLD at baseline, a resolution of NAFLD was found in 20 individuals. For 1 standard deviation increase in VO(2,max) at baseline the odds ratio for resolution of NAFLD was 2.79 (95% confidence interval, 1.43-6.33). CONCLUSIONS: Cardiorespiratory fitness, independently of total adiposity, body fat distribution and exercise intensity, determines liver fat content in humans, suggesting that fitness and liver fat are causally related to each other. Moreover, measurement of fitness at baseline predicts the effectiveness of a lifestyle intervention in reducing hepatic steatosis in patients with NAFLD.

Lifestyle intervention in individuals with normal versus impaired glucose tolerance.

BACKGROUND: Lifestyle intervention is effective in the prevention of type 2 diabetes in individuals with impaired glucose tolerance (IGT). It is currently unknown whether it has beneficial effects on metabolism to a similar extent, in individuals with normal glucose tolerance (NGT) compared to individuals with IGT. MATERIALS AND METHODS: Data from 181 subjects (133 with NGT and at risk for type 2 diabetes and 48 with IGT) who participated in the Tuebingen Lifestyle Intervention Program with increase in physical activity and decrease in caloric intake were included into this study. Body fat distribution was quantified by whole-body magnetic resonance (MR) tomography and liver fat and intramyocellular fat by (1)H-MR spectroscopy. Insulin sensitivity was estimated from an oral glucose tolerance test (OGTT). RESULTS: After 9 +/- 2 months of follow-up, the diagnosis of IGT was reversed in 24 out of 48 individuals. Only 14 out of 133 participants with NGT developed IGT. Body weight decreased in both groups by 3% (both P < 0.0001). Two-hour glucose concentrations during an OGTT decreased in individuals with IGT (-14%, P < 0.0001) but not with NGT (+2%, P = 0.66). Insulin sensitivity increased both in individuals with IGT (+9%, P = 0.04) and NGT (+17%, P < 0.0001). Visceral fat (-8%, P = 0.006), liver fat (-28%, P < 0.0001) and intramyocellular fat (-15%, P = 0.006) decreased in participants with IGT. In participants with NGT these changes were significant for visceral fat (-16%, P < 0.0001) and liver fat (-35%, P < 0.0001). CONCLUSIONS: Moderate weight loss under a lifestyle intervention with reduction in total, visceral and ectopic fat and increase in insulin sensitivity improves glucose tolerance in individuals with IGT but not with NGT. In individuals with NGT, the beneficial effects of a lifestyle intervention on fat distribution and insulin sensitivity possibly prevent future deterioration in glucose tolerance.