Changes in glucose metabolism in people with different glucose metabolism disorders at baseline: follow-up results of a Finnish national diabetes prevention programme.

AIM: To examine changes in glucose metabolism (fasting and 2-h glucose) during follow-up in people with impaired fasting glucose in comparison with changes in people with isolated impaired glucose tolerance, people with impaired fasting glucose and impaired glucose tolerance combined and people with screening-detected Type 2 diabetes at baseline, among those who participated in a diabetes prevention programme conducted in Finland. METHODS: A total of 10 149 people at high risk of Type 2 diabetes took part in baseline examination. Of 5351 individuals with follow-up ≥ 9 months, 1727 had impaired glucose metabolism at baseline and completed at least one lifestyle intervention visit. Most of them (94.6%) were overweight/ obese. RESULTS: Fasting glucose decreased during follow-up among overweight/obese people in the combined impaired fasting glucose and impaired glucose tolerance group (P = 0.044), as did 2-h glucose in people in the isolated impaired glucose tolerance group (P = 0.0014) after adjustment for age, sex, medication and weight at baseline, follow-up time and changes in weight, physical activity and diet. When comparing changes in glucose metabolism among people with different degrees of glucose metabolism impairment, fasting glucose concentration was found to have increased in those with isolated impaired glucose tolerance (0.12 mmol/l, 95% Cl 0.05 to 0.19) and it decreased to a greater extent in those with screening-detected Type 2 diabetes (-0.54 mmol/l, 95% Cl -0.69 to -0.39) compared with those with impaired fasting glucose (-0.21 mmol/l, 95% Cl -0.27 to -0.15). Furthermore, 2-h glucose concentration decreased in the isolated impaired glucose tolerance group (-0.82 mmol/l, 95% Cl -1.04 to -0.60), in the combined impaired fasting glucose and impaired glucose tolerance group (-0.82 mmol/l, 95% Cl -1.07 to -0.58) and in the screening-detected Type 2 diabetes group (-1.52, 95% Cl -1.96 to -1.08) compared with those in the impaired fasting glucose group (0.26 mmol/l, 95% Cl 0.10 to 0.43). Results were statistically significant even after adjustment for covariates (P < 0.001 in all models). CONCLUSIONS: Changes in glucose metabolism differ in people with impaired fasting glucose from those in people with isolated impaired glucose tolerance, people with impaired fasting glucose and impaired glucose tolerance combined and people with screening-detected Type 2 diabetes.

Fish consumption, omega-3 fatty acids, and environmental contaminants in relation to low-grade inflammation and early atherosclerosis.

BACKGROUND: Fish consumption and omega-3 polyunsaturated fatty acid (PUFA) intake are shown to protect from cardiovascular diseases (CVD). However, most fish contain environmental contaminants such as dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and methylmercury (MeHg) that may have adverse effects on cardiovascular health. OBJECTIVE: Our aim was to elucidate the associations of fish consumption, omega-3 PUFAs, environmental contaminants with low-grade inflammation, early atherosclerosis, and traditional CVD risk factors. METHODS: The Health 2000 survey participants (n=1173) represented the general Finnish population and the Fishermen study participants (n=255) represented a population with high fish consumption and high exposure to environmental contaminants. Model-adjusted geometric means and tests for linear trend were calculated for CVD risk factors by tertiles of fish consumption and serum omega-3 PUFAs, and additionally in the Fishermen study only, by tertiles of serum PCDD/F+PCB, and blood MeHg. RESULTS: Serum triglyceride decreased across omega-3 PUFA tertiles in both sexes and studies. Insulin resistance, C-reactive protein, tumour necrosis factor α, and interleukin 6 decreased across omega-3 PUFA tertiles among the Health 2000 survey participants. Among the Fishermen study men, insulin resistance and arterial stiffness indicated by ß-stiffness index tended to increase and the RR estimate for carotid artery plaque tended to decrease across tertiles of PCDD/F+PCB and MeHg. CONCLUSION: Previously established hypotriglyceridemic and anti-inflammatory effects of omega-3 PUFAs were seen also in this study. The hypothesised favourable effect on insulin sensitivity and arterial elasticity was suggested to be counteracted by high exposure to environmental contaminants but the effect on plaque prevalence appeared not to be harmful.

Conjugated bile acids associate with altered rates of glucose and lipid oxidation after Roux-en-Y gastric bypass.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (RYGB) induces a more favorable metabolic profile than expected by weight loss alone. In this study, we investigated the effect of RYGB on serum bile acid levels and their relation to clinical outcomes. METHODS: We included 30 obese patients who underwent RYGB (BMI = 46.1 ± 5.9 kg/m(2)). Clinical measurements and laboratory determinations were performed before surgery and 1 year after surgery. Fasting serum bile acids were measured by an enzymatic method and individual bile acids were quantified by HLPC-tandem mass spectrometry. Indirect calorimetry was performed to measure the rates of energy expenditure and substrate oxidation. RESULTS: Fasting total serum bile acid levels increased twofold after RYGB (pre, 3.68 ± 2.03 vs. post, 7.06 ± 9.65 µmol/l, +92 %, p = 0.002). This increase in total bile acids was accompanied by a decrease in conjugated bile acids, which correlated with decreased glucose oxidation (r = 0.571, p = 0.002) and with increased lipid oxidation (r = -0.626, p = 0.0004). The change in taurine-conjugated bile acids correlated with altered DIO2 mRNA expression in adipose tissue (r = -0.498, p = 0.013) potentially linking bile acid conjugation to substrate oxidation through DIO2. CONCLUSIONS: Fasting serum bile acid levels increase after RYGB. More specifically, changes in bile acid conjugation after RYGB associate with altered energy metabolism.

Regulation of metallothionein gene transcription. Identification of upstream regulatory elements and transcription factors responsible for cell-specific expression of the metallothionein genes from Caenorhabditis elegans.

Metallothioneins are small, cysteine-rich proteins that function in metal detoxification and homeostasis. Metallothionein transcription is controlled by cell-specific factors, as well as developmentally modulated and metal-responsive pathways. By using the nematode Caenorhabditis elegans as a model system, the mechanism that controls cell-specific metallothionein transcription in vivo was investigated. The inducible expression of the C. elegans metallothionein genes, mtl-1 and mtl-2, occurs exclusively in intestinal cells. Sequence comparisons of these genes with other C. elegans intestinal cell-specific genes identified multiple repeats of GATA transcription factor-binding sites (i.e. GATA elements). In vivo deletion and site-directed mutation analyses confirm that one GATA element in mtl-1 and two in mtl-2 are required for transcription. Electrophoretic mobility shift assays show that the C. elegans GATA transcription factor ELT-2 specifically binds to these elements. Ectopic expression of ELT-2 in non-intestinal cells of C. elegans activates mtl-2 transcription in these cells. Likewise, mtl-2 is not expressed in nematodes in which elt-2 has been disrupted. These results indicate that cell-specific transcription of the C. elegans metallothionein genes is regulated by the binding of ELT-2 to GATA elements in these promoters. Furthermore, a model is proposed where ELT-2 constitutively activates metallothionein expression; however, a second metal-responsive factor prevents transcription in the absence of metals.