Rongrong Cai

Disrupted resting-state attentional networks in T2DM patients

Although Type 2 diabetes mellitus (T2DM) is a well-recognized risk factor for dementia, the neural mechanisms that underlie cognitive impairment in T2DM remain unclear. This study uses resting-state functional magnetic resonance imaging (fMRI) to examine attention network alterations in T2DM and their relationships to impaired cognitive performance. Data-driven independent component analysis was applied to resting-state fMRI data from 38 T2DM patients and 32 healthy controls to identify the dorsal attention network (DAN) and ventral attention network (VAN). Correlations were then determined among the resting-state functional connectivity (rsFC), clinical data, and neuropsychological scores. The T2DM patients exhibited decreased rsFC in the left middle frontal gyrus (MFG) and bilateral inferior parietal lobe (IPL) of the DAN, as well as the left IPL and right MFG/IFG of the VAN. In addition, the rsFC of the left MFG was inversely correlated with the Trail Making Test-B scores; the rsFC of the left IPL was positively correlated with the Digit Span Test scores but negatively correlated with HbA1c; and the rsFC in the right precuneus was positively associated with cognitive performance (without Bonferroni correction). In conclusion, T2DM affects resting-state attentional networks, which may be related to reduced attention and a hyperglycemic state.

Statin therapy on glycaemic control in type 2 diabetes: a meta-analysis

Objective: Randomised controlled trials (RCTs) indicate that statin therapy has cardiovascular benefit among patients with type 2 diabetes. Recently, statins were reported to increase risk of diabetes by 9%. The aim was to investigate by a meta-analysis whether statins deteriorate glycaemic control in type 2 diabetes. Methods: Medline, EMBASE and Cochrane Central Register of Controlled Trials from 1966 to 2012 were searched for RCTs of statins. Included were only trials with type 2 diabetes. Main outcome measures: The I2 statistic was used to measure heterogeneity between trials and calculated mean differences for glycaemic parameters with random-effect meta-analysis. Results: 26 eligible studies were identified with 3232 participants. Statin therapy had no remarkable influence on HbA1c (WMD 0.04%, 95% CI -0.08 to 0.16, I² = 45.7%, n = 3070), FPG (2.25 mg/dl, 95% CI -3.50 to 7.99, I² = 46%, n = 1176), BMI, fasting insulin or HOMA-IR. However, subgroup analysis showed significant, detrimental effect of atorvastatin on HbA1c, whereas simvastatin presented an ameliorative effect. Meta-regression presented that neither baseline age nor relative reduction in LDL-cholesterol concentrations accounted for residual heterogeneity. Conclusion: Statin therapy showed non-significant effect on glycaemic control in type 2 diabetes. Statin therapy need not change among them with moderate or high cardiovascular risk or existing cardiovascular disease.

Lower Intensified Target LDL-c Level of Statin Therapy Results in a Higher Risk of Incident Diabetes: A Meta-Analysis

Background A recent meta-analysis has reported that intensive-dose statin drug increases the risk of incident diabetes. However, doubling of the statin dose generates only a further 6% decrease in low-density lipoprotein cholesterol (LDL-c) on average. This study aimed to determine whether statin therapy with lower intensive-target LDL-c level contributes to higher risk of new-onset diabetes. Methods Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched for randomized controlled endpoint trials of statins conducted from 1966 to 2012. We included trials with more than 1000 participants who were followed up for at least 2 years. The included trials were stratified by the target LDL-c level. I 2 statistic was used to measure heterogeneity between trials. We further calculated risk estimates with random-effect meta-analysis. Meta-regression was used to identify the potential risk factors of statin-induced diabetes. Results Fourteen trials with a total of 95 102 non-diabetic participants were included. The risks elevated by 33% [odds ratio (OR) = 1.33; 95% confidence interval (CI) 1.14–1.56; I 2 = 7.7%] and 16% (OR = 1.16; 95% CI 1.06–1.28; I 2 = 0.0%) when the intensified target LDL-c levels were ≤1.8 mmol/L and 1.8–2.59 mmol/L, respectively. The risk of incident diabetes did not increase when the target LDL-c level was ≥2.59 mmol/L. Apart from age, female, and baseline level of total cholesterol, meta-regression analysis showed that the target and baseline levels of LDL-c and relative LDL-c reduction were predictors of statin-induced diabetes. Conclusion A lower intensified target LDL-c level of statin therapy resulted in a higher risk of incident diabetes.

Insulin Resistance-Associated Interhemispheric Functional Connectivity Alterations in T2DM: A Resting-State fMRI Study

We aim to investigate whether decreased interhemispheric functional connectivity exists in patients with type 2 diabetes mellitus (T2DM) by using resting-state functional magnetic resonance imaging (rs-fMRI). In addition, we sought to determine whether interhemispheric functional connectivity deficits associated with cognition and insulin resistance (IR) among T2DM patients. We compared the interhemispheric resting state functional connectivity of 32 T2DM patients and 30 healthy controls using rs-fMRI. Partial correlation coefficients were used to detect the relationship between rs-fMRI information and cognitive or clinical data. Compared with healthy controls, T2DM patients showed bidirectional alteration of functional connectivity in several brain regions. Functional connectivity values in the middle temporal gyrus (MTG) and in the superior frontal gyrus were inversely correlated with Trail Making Test-B score of patients. Notably, insulin resistance (log homeostasis model assessment-IR) negatively correlated with functional connectivity in the MTG of patients. In conclusion, T2DM patients exhibit abnormal interhemispheric functional connectivity in several default mode network regions, particularly in the MTG, and such alteration is associated with IR. Alterations in interhemispheric functional connectivity might contribute to cognitive dysfunction in T2DM patients.

Blood Pressure is Associated With Cerebral Blood Flow Alterations in Patients With T2DM as Revealed by Perfusion Functional MRI.

AbstractType 2 diabetes mellitus (T2DM) and hypertension are both associated with cognitive impairment and brain function abnormalities. We investigated whether abnormal cerebral blood flow (CBF) patterns exists in T2DM patients and possible relationships between aberrant CBF and cognitive performance. Furthermore, we examined the influence of hypertension on CBF alterations in T2DM patients.T2DM patients (n = 38) and non-T2DM subjects (n = 40) were recruited from clinics, hospitals, and normal community health screenings. Cerebral blood flow images were collected and analyzed using arterial spin labeling perfusion functional magnetic resonance imaging (fMRI). Regions with major CBF differences between T2DM patients and non-T2DM controls were detected via 1-way ANOVA. The interaction effects between hypertension and T2DM for CBF alterations were also examined. Correlation analyses illustrated the association between CBF values and cognitive performance and between CBF and blood pressure.Compared with non-T2DM controls, T2DM patients exhibited decreased CBF, primarily in the visual area and the default mode network (DMN); decreased CBF in these regions was correlated with cognitive performance. There was a significant interaction effect between hypertension and diabetes for CBF in the precuneus and the middle occipital gyrus. Additionally, blood pressure correlated negatively with CBF in T2DM patients.T2DM patients exhibited reduced CBF in the visual area and DMN. Hypertension may facilitate a CBF decrease in the setting of diabetes. T2DM patients may benefit from blood pressure control to maintain their brain perfusion through CBF preservation.

Association between reductions in low-density lipoprotein cholesterol with statin therapy and the risk of new-onset diabetes: a meta-analysis.

A recent meta-analysis demonstrated that statin therapy was associated with a risk of diabetes. The present study investigated whether the relative reduction in low-density lipoprotein cholesterol (LDL-c) was a good indicator of the risk of new-onset diabetes. We searched the PubMed, Embase, Cochrane Central Register, Lilacs, Food and Drug Administration, and European Medicines Agency databases for randomized controlled trials of statins. Fourteen trials were included in the study. Eight trials with target LDL-c levels ≤100 mg/dL (2.6 mmol/L) or LDL-c reductions of at least 30% were extracted separately. The results showed that the overall risk of incident diabetes increased by 11% (OR = 1.11; 95% CI 1.03–1.20). The group with intensive LDL-c-lowering statin had an 18% increase in the likelihood of developing diabetes (OR = 1.18; 95% CI, 1.10–1.28). Furthermore, the risks of incident diabetes were 13% (OR = 1.13; 95% CI 1.01–1.26) and 29% (OR = 1.29; 95% CI 1.13–1.47) in the subgroups with 30–40% and 40–50% reductions in LDL-c, respectively, suggesting that LDL-c reduction may provide a dynamic risk assessment parameter for new-onset diabetes. In conclusion, LDL-c reduction is positively related to the risk of new-onset diabetes. When LDL-c is reduced by more than 30% during lipid-lowering therapy, blood glucose monitoring is suggested to detect incident diabetes in high-risk populations.

An investigation into the therapeutic effects of statins with metformin on polycystic ovary syndrome: a meta-analysis of randomised controlled trials

Objectives To investigate the therapeutic effects of statins with metformin on polycystic ovary syndrome (PCOS). Settings Endocrinology department. Participants MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials were searched until October 2014. Studies comparing statins and placebo, as well as the combination of statins and metformin and metformin alone, were included in the analysis. Interventions Data were independently extracted by two researchers; any convergence was resolved by a third reviewer. Primary and secondary outcome measures The following properties were extracted from the qualified trials to identify the effects of statins: clinical variables, metabolic characteristics, hormone outcomes, sign of inflammation, glucose parameters and insulin outcomes. Results Data from four trials comparing statin and metformin with metformin alone were analysed. The combination of statins and metformin decreases the levels of C reactive protein (standardised mean difference (SMD) −0.91; 95% CI −1.81 to −0.02; p=0.046), triglyceride (SMD −1.37; 95% CI −2.46 to −0.28; p=0.014), total cholesterol (SMD −1.28; 95% CI −1.59 to −0.97; p=0.000) and low-density lipoprotein (LDL) cholesterol (SMD −0.74; 95% CI −1.03 to −0.44; p=0.000). However, the combined therapy fails to reduce fasting insulin (SMD −0.92; 95% CI −2.07 to 0.24; p=0.120), homeostasis model assessment of insulin resistance (SMD −1.15; 95% CI −3.36 to 1.06; p=0.309) and total testosterone (SMD −1.12; 95% CI −2.29 to 0.05; p=0.061). Analysis of the five trials comparing statin with placebo shows that statin monotherapy reduces LDL-cholesterol, triglyceride and total cholesterol. Conclusions Combined statin and metformin therapy can improve lipid and inflammation parameters, but cannot effectively improve insulin sensitivity and reduce hyperandrogenism in women with PCOS. A large-scale randomised controlled study must be conducted to ascertain the long-term effects of the therapy.

RAGE and AGEs in Mild Cognitive Impairment of Diabetic Patients: A Cross-Sectional Study.

Objective Receptor for advanced glycation end products (AGEs; RAGE) binds to both AGEs and amyloid-beta peptides. RAGE is involved in chronic complications of type 2 diabetes and Alzheimer’s disease. We aimed to investigate the roles of RAGE, AGEs and the Gly82Ser polymorphism of RAGE in mild cognitive impairment (MCI) among type 2 diabetes patients. Methods Of the 167 hospitalized type 2 diabetes patients recruited, 82 satisfied the diagnostic criteria for MCI, and 85 matched control individuals were classified as non-MCI. Demographic data were collected, and the soluble RAGE (sRAGE) concentrations, serum AGE-peptide (AGE-P) levels, RAGE Gly82Ser genotype and neuropsychological test results were examined. Results The MCI group exhibited a decreased sRAGE level (0.87±0.35 vs. 1.05±0.52 ng/ml, p<0.01) and an increased serum AGE-P level (3.54±1.27 vs. 2.71±1.18 U/ml, p<0.01) compared with the control group. Logistic regression analysis indicated that each unit reduction in the sRAGE concentration increased the MCI risk by 54% (OR 0.46[95% CI 0.22–0.96], p = 0.04) and that each unit increase in the AGE-P level increased the MCI risk by 72% in the type 2 diabetes patients (OR 1.72[95% CI 1.31–2.28], p<0.01). The serum sRAGE level was negatively correlated with the score on the trail making test-B (TMT-B) (r = -0.344, p = 0.002), which indicates early cognitive deficits related to diabetes. Moreover, the AGE-P level was positively correlated with multiple cognitive domains (all p<0.05). No significant differences in the neuropsychological test results or serum RAGE concentrations between the different RAGE genotypes or in the RAGE genotype frequencies between the MCI and control groups were identified (all p>0.05). Conclusions The RAGE pathway partially mediates AGE-induced MCI in diabetic patients. The serum AGE-P level may serve as a serum biomarker of MCI in these individuals, and sRAGE represents a predictor and even a potential intervention target of early cognitive decline in type 2 diabetes patients. Trial registration Advanced Glycation End Products Induced Cognitive Impairment in Diabetes: BDNF Signal Meditated Hippocampal Neurogenesis ChiCTR-OCC-15006060

Diabetes mellitus as a risk factor for incident chronic kidney disease and end-stage renal disease in women compared with men: a systematic review and meta-analysis

Diabetes mellitus is a strong risk factor for chronic kidney disease and end-stage renal disease. Whether sex differences in chronic kidney disease and end-stage renal disease incidence exist among diabetic patients remains unclear. This systematic review and meta-analysis was conducted to evaluate the relative effect of diabetes on chronic kidney disease and end-stage renal disease risk in women compared with men. We systematically searched Embase, PubMed, and the Cochrane Library for both cohort and case–control studies until October 2015. Studies were selected if they reported a sex-specific relationship between diabetes mellitus and chronic kidney disease or end-stage renal disease. We generated pooled estimates across studies using random-effects meta-analysis after log transformation with inverse variance weighting. Ten studies with data from more than 5 million participants were included. The pooled adjusted risk ratio of chronic kidney disease associated with diabetes mellitus was 3.34 (95 % CI 2.27, 4.93) in women and 2.84 (95 % CI 1.73, 4.68) in men. The data showed no difference in diabetes-related chronic kidney disease risk between the sexes (pooled adjusted women-to-men relative risk ratio was 1.14 [95 % CI 0.97, 1.34]) except for end-stage renal disease—the pooled adjusted women-to men relative risk ratio was 1.38 (95 % CI 1.22, 1.55; p = 0.114, I² = 38.1 %). The study found no evidence of a sex difference in the association between diabetes mellitus and chronic kidney disease. However, the excess risk for end-stage renal disease was higher in women with diabetes than in men with the same condition, from which we assume that the female gender could accelerate the disease progression. Further studies are needed to support this notion and elucidate the underlying mechanisms.

Statins worsen glycemic control of T2DM in target LDL-c level and LDL-c reduction dependent manners: a meta-analysis

ABSTRACT Objective: Recent studies demonstrated that a low target low-density lipoprotein cholesterol (LDL-c) level, high LDL-c reduction and high dose of statin therapy increased incident diabetes. This study aimed to explore how statin therapy influences glycemic control in type 2 diabetes mellitus (T2DM). Methods: Medline, Embase, and Cochrane Central were searched for randomized control trials inT2DM. Trials with target LDL-c levels of ≤2.6 mmol/L or LDL-c reduction of ≥30% were analyzed. Then, we calculated mean differences in glycosylated hemoglobin (HbA1c) and fasting blood glucose via stratified LDL-c level, relative LDL-c reduction and statin dose. Results: In total, trials involving 6,875 participants (3,619 statins, 3,256 controls) were included. Meta-analysis showed that detrimental effect of intensive LDL-c lowering statin therapy on HbA1c (SMD 0.10%; 95% CI 0.05, 0.15; p = 0.000) was more severe than all statin trials analyzed together (SMD 0.07%; 95% CI 0.02, 0.12; p = 0.005). Stratified analyses revealed that the effects on HbA1c became increasingly significant as target LDL-c level decreased and LDL-c reduction increased. Low baseline LDL-c and endpoint LDL-c levels were risk factors involved in increasing HbA1c level during statin therapy. Conclusions: Statin therapy worsens the glycemic control of T2DM in target LDL-c level and LDL-c reduction dependent manners.