Cost-effectiveness of a lifestyle intervention in preventing Type 2 diabetes.

OBJECTIVES: Previous research has suggested people with impaired fasting glucose (IFG) are less likely to develop Type 2 diabetes (T2DM) if they receive prolonged structured diet and exercise advice. This study examined the within-trial cost-effectiveness of such lifestyle interventions. METHODS: Screen-detected participants with either newly diagnosed T2DM or IFG were randomized 2:1 to intervention versus control (usual care) between February and December 2009, in Norfolk (UK). The intervention consisted of group based education, physiotherapy and peer support sessions, plus telephone contacts from T2DM volunteers. We monitored healthcare resource use, intervention costs, and quality of life (EQ-5D). The incremental cost per quality-adjusted life-year (QALY) gain (incremental cost effectiveness ratio [ICER]), and cost effectiveness acceptability curves (CEAC) were estimated. RESULTS: In total, 177 participants were recruited (118 intervention, 59 controls), with a mean follow-up of 7 months. Excluding screening and recruitment costs, the mean cost was estimated to be £551 per participant in the intervention arm, compared with £325 in the control arm. The QALY gains were -0.001 and -0.004, respectively. The intervention was estimated to have an ICER of £67,184 per QALY (16 percent probability of being cost-effective at the £20,000/QALY threshold). Cost-effectiveness estimates were more favorable for IFG participants and those with longer follow-up (≥ 4 months) (ICERs of £20,620 and £17,075 per QALY, respectively). CONCLUSIONS: Group sessions to prevent T2DM were not estimated to be within current limits of cost-effectiveness. However, there was a large degree of uncertainty surrounding these estimates, suggesting the need for further research.

Quantitative measurement of sulforaphane, iberin and their mercapturic acid pathway metabolites in human plasma and urine using liquid chromatography-tandem electrospray ionisation mass spectrometry.

A quantitative liquid chromatography positive ion electrospray tandem mass spectrometric method for the simultaneous determination of sulforaphane, iberin and their metabolites in human urine and plasma is described. The stability of the metabolites was determined in aqueous solution and in human plasma. Gradient liquid chromatographic separation was performed on a Zorbax SB-Aq 3.5 microm (100 x 2.1mm) column, using a mobile phase (flow rate 0.25 mL/min) consisting of ammonium acetate buffer at pH 4 and acetonitrile. Butyl thiocarbamoyl l-cysteine was used as internal standard. The assay was linear (r(2)>0.99) over the range of 0.03-300 microM in urine and 0.03-15 microM in plasma with intra- and inter-day assay precision (<10% CV) and accuracy (<20%). The lower limits of quantitation were in the range of 10-150 nmol/L. The method has been used to report, for the first time, individual quantitative measurement of each of the mercapturic acid pathway metabolites of sulforaphane and iberin in both human plasma and urine following a dietary study of broccoli consumption.

Glutathione S-transferase M1 polymorphism and metabolism of sulforaphane from standard and high-glucosinolate broccoli.

BACKGROUND: Broccoli consumption is associated with a reduction in the risk of cancer, particularly in persons with a functional glutathione S-transferase M1 allele, as opposed rotrose whose GSTM1 gene has been deleted. Sulforaphane, the major isothiocyanate derived from 4-methylsulfinylbutyl glucosinolate, is thought to be the main agent conferring protection. OBJECTIVE: We compared sulforaphane metabolism in GSTM1-null and GSTM1-positive subjects after they consumed standard broccoli and high-glucosinolate broccoli (super broccoli). DESIGN: Sixteen subjects were recruited into a randomized, 3-phase crossover dietary trial of standard broccoli, super broccoli, and water. Liquid chromatography linked to tandem mass spectrometry was used to quantify sulforaphane and its thiol conjugates in plasma and urine. RESULTS: GSTM1-null subjects had slightly higher, but statistically significant, areas under the curve for sulforaphane metabolite concentrations in plasma, a greater rate of urinary excretion of sulforaphane metabolites during the first 6 h after broccoli consumption, and a higher percentage of sulforaphane excretion 24 h after ingestion than did GSTM1-positive subjects. Consumption of high-glucosinolate broccoli led to a 3-fold greater increase in the areas under the curve and maximum concentrations of sulforaphane metabolites in plasma, a greater rate of urinary excretion of sulforaphane metabolites during the first 6 h after consumption, and a lower percentage of sulforaphane excretion after its ingestion than did the consumption of standard broccoli. CONCLUSIONS: GSTM1 genotypes have a significant effect on the metabolism of sulforaphane derived from standard or high-glucosinolate broccoli. It is possible that the difference in metabolism may explain the greater protection that GSTM1-positive persons gain from consuming broccoli. The potential consequences of consuming glucosinolate-enriched broccoli for GSTM1-null and -positive persons are discussed.

A motivational peer support program for type 2 diabetes prevention delivered by people with type 2 diabetes: the UEA-IFG feasibility study.

PURPOSE: The purpose of this study was to develop a peer support program for individuals at high risk of type 2 diabetes as part of a novel Diabetes Prevention Programme (The UEA-IFG Study). Lay members of the public with existing type 2 diabetes volunteered as peer supporters (termed type 2 trainers) for participants at high risk of developing type 2 diabetes. The feasibility of type 2 trainer recruitment, training, and retention was tested. METHODS: Between January and September 2009, 1500 potential type 2 trainers with existing type 2 diabetes were contacted and 168 (11%) expressed an interest. From this group, 26 type 2 trainers were appointed to begin training. All completed 7 training seminars, covering diabetes prevention, nutrition, physical activity, listening skills, motivation, and goal planning. Motivational calls were made every 12 weeks to each study participant by each type 2 trainer in addition to health care professional-delivered education sessions. RESULTS: Twenty-six type 2 trainers were recruited to enter the program. One type 2 trainer withdrew before beginning their role. The retention rate was high, with 22 (89%) of the type 2 trainers continuing until study end (July 2010; 20 months), with a total of 240 phone calls made. CONCLUSION: The recruiting and training of lay volunteers with existing type 2 diabetes as type 2 trainers to support study participants at risk of developing the same condition was a cost-effective strategy in comparison to employing salaried health care professionals and warrants further investigation on health outcomes.

Broccoli consumption interacts with GSTM1 to perturb oncogenic signalling pathways in the prostate.

BACKGROUND: Epidemiological studies suggest that people who consume more than one portion of cruciferous vegetables per week are at lower risk of both the incidence of prostate cancer and of developing aggressive prostate cancer but there is little understanding of the underlying mechanisms. In this study, we quantify and interpret changes in global gene expression patterns in the human prostate gland before, during and after a 12 month broccoli-rich diet. METHODS AND FINDINGS: Volunteers were randomly assigned to either a broccoli-rich or a pea-rich diet. After six months there were no differences in gene expression between glutathione S-transferase mu 1 (GSTM1) positive and null individuals on the pea-rich diet but significant differences between GSTM1 genotypes on the broccoli-rich diet, associated with transforming growth factor beta 1 (TGFbeta1) and epidermal growth factor (EGF) signalling pathways. Comparison of biopsies obtained pre and post intervention revealed more changes in gene expression occurred in individuals on a broccoli-rich diet than in those on a pea-rich diet. While there were changes in androgen signalling, regardless of diet, men on the broccoli diet had additional changes to mRNA processing, and TGFbeta1, EGF and insulin signalling. We also provide evidence that sulforaphane (the isothiocyanate derived from 4-methylsuphinylbutyl glucosinolate that accumulates in broccoli) chemically interacts with TGFbeta1, EGF and insulin peptides to form thioureas, and enhances TGFbeta1/Smad-mediated transcription. CONCLUSIONS: These findings suggest that consuming broccoli interacts with GSTM1 genotype to result in complex changes to signalling pathways associated with inflammation and carcinogenesis in the prostate. We propose that these changes may be mediated through the chemical interaction of isothiocyanates with signalling peptides in the plasma. This study provides, for the first time, experimental evidence obtained in humans to support observational studies that diets rich in cruciferous vegetables may reduce the risk of prostate cancer and other chronic disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT00535977.

Consuming broccoli does not induce genes associated with xenobiotic metabolism and cell cycle control in human gastric mucosa.

Epidemiological studies suggest that a diet rich in broccoli can reduce the risk of cancer at several sites. The anticarcinogenic activity has been largely attributed to the biological activity of sulforaphane (SF), the isothiocyanate derived from 4-methylsulphinylbutyl glucosinolate, which accumulates in broccoli. SF induces xenobiotic metabolizing genes in both cell cultures and animal models and induces genes associated with cell cycle arrest and apoptosis. However, it is not known whether these genes are induced in humans after consumption of broccoli. Sixteen subjects were recruited into a randomized, 3-phase crossover dietary trial of standard broccoli, high glucosinolate broccoli, and water. Global changes in gene expression that occurred 6 h after consuming broccoli soups or water were quantified in gastric mucosal tissue, using Affymetrix whole genome microarrays (n = 4), and in selected genes by real-time RT-PCR in the other individuals. Consumption of high glucosinolate broccoli resulted in up-regulation of several xenobiotic metabolizing genes, including thioredoxin reductase, aldoketoreductases, and glutamate cysteine ligase modifier subunit, which have previously been reported to be induced in cell and animal models after exposure to SF. Only 1 such gene was significantly up-regulated after consumption of standard broccoli. The consequences of these results in relation to the potential anticarcinogenic action of broccoli are discussed.

Transcriptome analysis of human colon Caco-2 cells exposed to sulforaphane.

Sulforaphane (SF), a dietary phytochemical obtained from broccoli, has been implicated in several physiological processes consistent with anticarcinogenic activity, including enhanced xenobiotic metabolism, cell cycle arrest, and apoptosis. In this study, we report changes in global gene expression in Caco-2 cells exposed to physiologically appropriate concentrations of SF, through the use of replicated Affymetrix array and RT-PCR experiments. After exposure to 50 micromol/L SF, 106 genes exhibited a >2-fold increase in expression and 63 genes exhibited a >2-fold decrease in expression. There were fewer changes in gene expression at lower SF concentrations. The majority of these genes had not previously been shown to be modulated by SF, suggesting novel mechanisms of possible anticarcinogenic activity, including induction of differentiation and modulation of fatty acid metabolism. The changes in the expression of 10 of these genes, together with 4 additional genes of biological interest, were further quantified in independent studies with RT-PCR. These genes include several that have recently become associated with carcinogenesis, such as Krüppel-like factor (KLF)4, a gut-enriched transcription factor associated with induction of differentiation and reduction in cellular proliferation; DNA (cytosine-5-)-methyltransferase 1, associated with methylation; and alpha-methylacyl-CoA racemase (AMACR), a marker associated with the development of colon and prostate cancer. The expression of 5 of these genes [caudal type homeo box transcription factor 2 (CDX-2), KLF4, KLF5, cyclin-dependent kinase inhibitor 1A (p21), and AMACR] was additionally studied after in vitro exposure to SF of surgically resected healthy and cancerous colon tissue from each of 3 patients. The study suggests the complex effects that SF has on gene expression and highlights several potential mechanisms by which the consumption of broccoli may reduce the risk of carcinogenesis.