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The American Journal of Psychiatry Apr 2015Public health campaigns encouraging early help seeking have increased rates of mild cognitive impairment (MCI) diagnosis in Western countries, but we know little about... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Public health campaigns encouraging early help seeking have increased rates of mild cognitive impairment (MCI) diagnosis in Western countries, but we know little about how to treat or predict dementia outcomes in persons with the condition.
METHOD
The authors searched electronic databases and references for longitudinal studies reporting potentially modifiable risk factors for incident dementia after MCI. Two authors independently evaluated study quality using a checklist. Meta-analyses were conducted of three or more studies.
RESULTS
There were 76 eligible articles. Diabetes and prediabetes increased risk of conversion from amnestic MCI to Alzheimer's dementia; risk in treated versus untreated diabetes was lower in one study. Diabetes was also associated with increased risk of conversion from any-type or nonamnestic MCI to all-cause dementia. Metabolic syndrome and prediabetes predicted all-cause dementia in people with amnestic and any-type MCI, respectively. Mediterranean diet decreased the risk of conversion to Alzheimer's dementia. The presence of neuropsychiatric symptoms or lower serum folate levels predicted conversion from any-type MCI to all-cause dementia, but less formal education did not. Depressive symptoms predicted conversion from any-type MCI to all-cause dementia in epidemiological but not clinical studies.
CONCLUSIONS
Diabetes increased the risk of conversion to dementia. Other prognostic factors that are potentially manageable are prediabetes and the metabolic syndrome, neuropsychiatric symptoms, and low dietary folate. Dietary interventions and interventions to reduce neuropsychiatric symptoms, including depression, that increase risk of conversion to dementia may decrease new incidence of dementia.
Topics: Alzheimer Disease; Cognitive Dysfunction; Dementia; Depression; Diabetes Mellitus; Diet, Mediterranean; Disease Progression; Educational Status; Folic Acid; Humans; Longitudinal Studies; Metabolic Syndrome; Prediabetic State; Protective Factors; Risk Factors
PubMed: 25698435
DOI: 10.1176/appi.ajp.2014.14070878 -
BMJ Open Nov 2017Explore the cost-effectiveness of lifestyle interventions and metformin in reducing subsequent incidence of type 2 diabetes, both alone and in combination with a... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Explore the cost-effectiveness of lifestyle interventions and metformin in reducing subsequent incidence of type 2 diabetes, both alone and in combination with a screening programme to identify high-risk individuals.
DESIGN
Systematic review of economic evaluations.
DATA SOURCES AND ELIGIBILITY CRITERIA
Database searches (Embase, Medline, PreMedline, NHS EED) and citation tracking identified economic evaluations of lifestyle interventions or metformin alone or in combination with screening programmes in people at high risk of developing diabetes. The International Society for Pharmaco-economics and Outcomes Research's Questionnaire to Assess Relevance and Credibility of Modelling Studies for Informing Healthcare Decision Making was used to assess study quality.
RESULTS
27 studies were included; all had evaluated lifestyle interventions and 12 also evaluated metformin. Primary studies exhibited considerable heterogeneity in definitions of pre-diabetes and intensity and duration of lifestyle programmes. Lifestyle programmes and metformin appeared to be cost effective in preventing diabetes in high-risk individuals (median incremental cost-effectiveness ratios of £7490/quality-adjusted life-year (QALY) and £8428/QALY, respectively) but economic estimates varied widely between studies. Intervention-only programmes were in general more cost effective than programmes that also included a screening component. The longer the period evaluated, the more cost-effective interventions appeared. In the few studies that evaluated other economic considerations, budget impact of prevention programmes was moderate (0.13%-0.2% of total healthcare budget), financial payoffs were delayed (by 9-14 years) and impact on incident cases of diabetes was limited (0.1%-1.6% reduction). There was insufficient evidence to answer the question of (1) whether lifestyle programmes are more cost effective than metformin or (2) whether low-intensity lifestyle interventions are more cost effective than the more intensive lifestyle programmes that were tested in trials.
CONCLUSIONS
The economics of preventing diabetes are complex. There is some evidence that diabetes prevention programmes are cost effective, but the evidence base to date provides few clear answers regarding design of prevention programmes because of differences in denominator populations, definitions, interventions and modelling assumptions.
Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Humans; Life Style; Metformin; Prediabetic State; Preventive Health Services; Quality-Adjusted Life Years; Randomized Controlled Trials as Topic
PubMed: 29146638
DOI: 10.1136/bmjopen-2017-017184 -
Diabetes, Obesity & Metabolism Dec 2022Very low carbohydrate/ketogenic diets (VLC/KDs) are popular but their role in managing pre-diabetes and type 2 diabetes (T2D) is uncertain. This study uses a systematic... (Meta-Analysis)
Meta-Analysis
AIM
Very low carbohydrate/ketogenic diets (VLC/KDs) are popular but their role in managing pre-diabetes and type 2 diabetes (T2D) is uncertain. This study uses a systematic review and meta-analysis of randomized controlled trials to estimate the effect of these diets in this population.
MATERIALS AND METHODS
A systematic review identified randomized controlled trials of at least 6 months duration comparing efficacy and safety of VLC/KDs (≤50 g carbohydrate or ≤10% total energy from carbohydrate per day) with a control diet (carbohydrate above the VLC/KD threshold) in adults with pre-diabetes or T2D. The primary outcome variable was glycated haemoglobin (HbA1c) after 12 months. The meta-analysis method was inverse variance weighting of mean values for continuous variables.
RESULTS
Key word searches identified 2290 studies; 2221 were not in scope. A full text review of 69 studies identified eight meeting inclusion criteria; in total, it involved 606 participants. Six studies reported HbA1c (%) at 12 months; four as change from baseline with a fixed effects estimate (95% confidence interval): VLC/KD minus control of 0.01% (-0.22 to 0.25), p = .91; and two as change from baseline: -0.65% (-0.99; -0.31) [-7.1 mmol/mol (-10.8; -3.4)], p < .001. Serum triglycerides were lower with VLC/KD versus control: -0.28 mmol/L (-0.44 to -0.11), p < .001. High-density lipoprotein was higher with an estimate of 0.04 mmol/L (0.01 to 0.08), p = .03, in the five studies reporting 12-month summary data.
CONCLUSIONS
A VLC/KD may cause reductions in HbA1c and triglycerides in those with pre-diabetes or T2D but evidence of an advantage over other strategies is limited. More well-designed studies are required to provide certain evidence.
Topics: Adult; Humans; Diabetes Mellitus, Type 2; Glycated Hemoglobin; Diet, Ketogenic; Prediabetic State; Randomized Controlled Trials as Topic; Diet, Carbohydrate-Restricted; Triglycerides
PubMed: 36064937
DOI: 10.1111/dom.14837 -
The Cochrane Database of Systematic... Oct 2018Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.
OBJECTIVES
To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.
SEARCH METHODS
We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.
SELECTION CRITERIA
We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.
DATA COLLECTION AND ANALYSIS
One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.
MAIN RESULTS
We included 103 prospective cohort studies. The studies mainly defined IH by IFG (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG, IFG, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG and IFG. Limited data showed a higher T2DM incidence associated with HbA1c compared to HbA1c. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.
AUTHORS' CONCLUSIONS
Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Disease Progression; Humans; Hyperglycemia; Incidence; Prediabetic State; Prognosis; Prospective Studies
PubMed: 30371961
DOI: 10.1002/14651858.CD012661.pub2 -
Andrology Feb 2023Type 2 diabetes mellitus and pre-diabetes are associated with reduced circulating testosterone levels. However, the role of testosterone replacement therapy in these... (Review)
Review
BACKGROUND
Type 2 diabetes mellitus and pre-diabetes are associated with reduced circulating testosterone levels. However, the role of testosterone replacement therapy in these patients is still conflicting.
OBJECTIVES
To summarize and critically analyze available data on the possible effect of testosterone administration in men with glucose abnormalities.
MATERIALS AND METHODS
A comprehensive systematic review was performed. When available, meta-analytic data were preferred. To better analyze the relationship between testosterone and the pre-diabetes condition, a systematic analysis was performed and the data obtained with the latter search were used for a meta-analytic approach. Finally, clinical data derived from a consecutive series of 4682 patients seeking medical care for sexual dysfunction at the University of Florence were also considered.
RESULTS
Patients with impaired fasting glucose were characterized by a 3 nmol/L lower level of total testosterone when compared to controls. Similarly, impaired fasting glucose was associated with a 1.8-fold increased risk of hypogonadism, when compared to subjects with normal glucose levels. Waist circumference and body mass index resulted as being the best predictors of reduced total testosterone levels. Secondary hypogonadism was two times higher in subjects with impaired fasting glucose when compared to rates observed in the general population. Testosterone replacement therapy was able to improve body composition, insulin resistance, and glucose profile both in impaired fasting glucose and type 2 diabetes mellitus whereas its role on body weight, lipid profile, and sexual function was less evident.
DISCUSSION AND CONCLUSION
Weight loss and physical activities are able to improve both metabolic profile and testosterone levels. The combined approach of testosterone replacement therapy and lifestyle modifications could be suggested in symptomatic hypogonadal men to better motivate patients to perform physical activity which can eventually result in weight loss as well as metabolic profile and sexual function improvement. Whether or not these approaches can prevent the development of type 2 diabetes mellitus from pre-clinical conditions requires more studies.
Topics: Male; Humans; Testosterone; Diabetes Mellitus, Type 2; Prediabetic State; Hypogonadism; Weight Loss; Glucose; Hormone Replacement Therapy
PubMed: 36542412
DOI: 10.1111/andr.13367 -
Diabetes & Metabolism Journal Sep 2023In May 2023, the Committee of Clinical Practice Guidelines of the Korean Diabetes Association published the revised clinical practice guidelines for Korean adults with... (Review)
Review
In May 2023, the Committee of Clinical Practice Guidelines of the Korean Diabetes Association published the revised clinical practice guidelines for Korean adults with diabetes and prediabetes. We incorporated the latest clinical research findings through a comprehensive systematic literature review and applied them in a manner suitable for the Korean population. These guidelines are designed for all healthcare providers nationwide, including physicians, diabetes experts, and certified diabetes educators who manage patients with diabetes or individuals at risk of developing diabetes. Based on recent changes in international guidelines and the results of a Korean epidemiological study, the recommended age for diabetes screening has been lowered. In collaboration with the relevant Korean medical societies, recently revised guidelines for managing hypertension and dyslipidemia in patients with diabetes have been incorporated into this guideline. An abridgment containing practical information on patient education and systematic management in the clinic was published separately.
Topics: Adult; Humans; Asian People; Dyslipidemias; Prediabetic State; Republic of Korea; Societies, Medical; Diabetes Mellitus
PubMed: 37793979
DOI: 10.4093/dmj.2023.0282 -
Journal of Diabetes Investigation Oct 2023There has been conflicting evidence regarding the role of prediabetes as a risk factor of lung cancer. A systemic review and meta-analysis was conducted to determine the... (Meta-Analysis)
Meta-Analysis
AIMS/INTRODUCTION
There has been conflicting evidence regarding the role of prediabetes as a risk factor of lung cancer. A systemic review and meta-analysis was conducted to determine the relationship between prediabetes and lung cancer incidence and mortality in general adult populations.
MATERIALS AND METHODS
Observational studies relevant to the objective were found in Medline, Embase, Cochrane Library, and Web of Science. By incorporating potential heterogeneity into the model, a randomized-effects model was selected.
RESULTS
Ten cohort studies were included. People with prediabetes were associated with a mildly increased risk of lung cancer incidence compared with controls with normoglycemia (risk ratio [RR]: 1.09, 95% confidence interval [CI]: 1.01-1.18, P = 0.03; I = 79%), which was mainly observed in men rather than in women (RR: 1.07 vs 0.99, P for subgroup difference < 0.001). Prediabetes was related to a higher risk of lung cancer mortality (RR: 1.19, 95% CI: 1.02-1.39, P = 0.03; I = 52%), and the results were consistent in both men and women (P for subgroup difference = 0.67). The association between prediabetes and lung cancer incidence or mortality did not appear to be significantly affected by different definitions of prediabetes (P for subgroup difference = 0.27 and 0.37).
CONCLUSIONS
Prediabetes might be associated with a mildly increased risk of lung cancer incidence in men, but not in women. In addition, prediabetes may be related to a higher risk of lung cancer mortality in the adult population.
Topics: Male; Adult; Humans; Female; Incidence; Prediabetic State; Lung Neoplasms; Risk Factors
PubMed: 37517054
DOI: 10.1111/jdi.14057 -
Environment International Jan 2022Cadmium exposure has been associated with increased diabetes risk in several studies, though there is still considerable debate about the magnitude and shape of the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cadmium exposure has been associated with increased diabetes risk in several studies, though there is still considerable debate about the magnitude and shape of the association.
OBJECTIVE
To perform a systematic review and meta-analysis of observational studies investigating the relation between cadmium exposure and risk of type 2 diabetes and prediabetes, and to summarize data on the magnitude and shape of the association.
DATA SOURCE
After conducting an online literature search through October 1, 2021, we identified 42 eligible studies investigating the association between cadmium exposure and risk of diabetes and prediabetes.
STUDY ELIGIBILITY CRITERIA
We included studies that assessed cadmium exposure through biomarker levels; examined type 2 diabetes or prediabetes among outcomes; and reported effect estimates for cadmium exposure for meta-analysis only.
STUDY APPRAISAL AND SYNTHESIS METHODS
Studies were evaluated using ROBINS-E risk of bias tool. We quantitively assessed the relation between exposure and study outcomes using one-stage dose-response meta-analysis with a random effects meta-analytical model.
RESULTS
In the meta-analysis, comparing highest-versus-lowest cadmium exposure levels, summary relative risks (RRs) for type 2 diabetes were 1.24 (95% confidence interval 0.96-1.59), 1.21 (1.00-1.45), and 1.47 (1.01-2.13) for blood, urinary, and toenail matrices, respectively. Similarly, there was an increased risk of prediabetes for cadmium concentrations in both urine (RR = 1.41, 95% CI: 1.15-1.73) and blood (RR = 1.38, 95% CI: 1.16-1.63). In the dose-response meta-analysis, we observed a consistent linear positive association between cadmium exposure and diabetes risk, with RRs of 1.25 (0.90-1.72) at 2.0 µg/g of creatinine. Conversely for blood cadmium, diabetes risk appeared to increase only above 1 µg/L. Prediabetes risk increased up to approximately 2 µg/g creatinine above which it reached a plateau with RR of 1.42 (1.12-1.76) at 2 µg/g creatinine.
LIMITATIONS AND CONCLUSIONS
This analysis provides moderate-certainty evidence for a positive association between cadmium exposure (measured in multiple matrices) and risk of both diabetes and prediabetes.
Topics: Bias; Cadmium; Diabetes Mellitus, Type 2; Humans; Prediabetic State; Risk
PubMed: 34628255
DOI: 10.1016/j.envint.2021.106920 -
Association between magnesium concentrations and prediabetes: a systematic review and meta-analysis.Scientific Reports Dec 2021Studies on the association between serum magnesium level and prediabetes yielded inconsistent results. Therefore, the present meta-analysis was designed to examine the... (Meta-Analysis)
Meta-Analysis
Studies on the association between serum magnesium level and prediabetes yielded inconsistent results. Therefore, the present meta-analysis was designed to examine the association between serum magnesium levels and prediabetes. Online databases including PubMed, Embase, Scopus and Google Scholar were searched up to October, 2020. A total of 10 studies that reported mean and standard deviation (SD) of magnesium levels in prediabetes and healthy control group were identified. Random effects models were used to pool weighted mean differences (WMDs) of serum magnesium levels. Pooled-analysis showed that subjects with prediabetes had significantly lower serum magnesium levels compared with healthy controls (WMD = - 0.07 mmol/L; 95% CI - 0.09, - 0.05 mmol/L, P < 0.001). A significant heterogeneity observed across included studies (I = 95.6%, P < 0.001). However, different subgroup analysis did not detect the potential source of observed heterogeneity. Withdrawal of each individual study had no effect on the overall results. The present meta-analysis showed that circulating magnesium levels in people with prediabetes were significantly lower than healthy controls, confirming that magnesium deficiency may play a role in development and progression of prediabetes. Further studies with larger sample size and robust design are warranted to confirm present results.
Topics: Humans; Magnesium; Magnesium Deficiency; Prediabetic State
PubMed: 34937856
DOI: 10.1038/s41598-021-03915-3 -
Frontiers in Public Health 2021Prediabetes is a borderline glycemic status associated with both higher incidence of cardiovascular disease as well as higher risk of progression to diabetes. There is a... (Meta-Analysis)
Meta-Analysis
Prediabetes is a borderline glycemic status associated with both higher incidence of cardiovascular disease as well as higher risk of progression to diabetes. There is a rising burden of diabetes and prediabetes globally. This study aims to estimate the burden of prediabetes in Nigeria. Online searches of Google Scholar, PubMed, and Scopus were conducted and studies were selected based on predefined criteria. A total of 15 studies consisting of 14,206 individuals conducted between 2000 and 2019 were included in the meta-analysis with studies using American Diabetic Association (ADA) and World Health Organization (WHO) criteria pooled separately. The pooled prevalence of prediabetes in Nigeria was found to be 13.2% (95% CI: 5.6-23.2%, = 98.4%) using the ADA criteria and 10.4% (95% CI: 4.3-18.9%, = 99.2%) using the WHO criteria. According to the latest data by the United Nations, this translates to an estimated 15.8 and 12.5 million adult prediabetic individuals in Nigeria using the ADA and WHO criteria, respectively. The prevalence rates for women and men were similar at 12.1% (95% CI: 5-21%). The pooled prevalence rates for urban and rural settlements were also similar at 9% (95% CI: 2-22%). In conclusion, the prevalence of prediabetes in Nigeria was almost two times higher than the 7.3% estimate by the International Diabetes Federation in 2003. The similar rates of prediabetes between men and women and between urban and rural settlements points toward narrowing of cardiovascular risk burden between the two sexes and the two settlements. This represents higher future cardiovascular disease burden in the country further pressurizing the overstretched healthcare system.
Topics: Adult; Cardiovascular Diseases; Diabetes Mellitus; Female; Humans; Male; Nigeria; Prediabetic State; Prevalence
PubMed: 35004577
DOI: 10.3389/fpubh.2021.762429