Effect of an anxiolytic on lipid profile in non-insulin-dependent diabetes mellitus

Metagenomic compendium of 189,680 DNA viruses from the human gut microbiome

Bacteriophages have important roles in the ecology of the human gut microbiome but are under-represented in reference databases. To address this problem, we assembled the Metagenomic Gut Virus catalogue that comprises 189,680 viral genomes from 11,810 publicly available human stool metagenomes. Over 75% of genomes represent double-stranded DNA phages that infect members of the Bacteroidia and Clostridia classes. Based on sequence clustering we identified 54,118 candidate viral species, 92% of which were not found in existing databases. The Metagenomic Gut Virus catalogue improves detection of viruses in stool metagenomes and accounts for nearly 40% of CRISPR spacers found in human gut Bacteria and Archaea. We also produced a catalogue of 459,375 viral protein clusters to explore the functional potential of the gut virome. This revealed tens of thousands of diversity-generating retroelements, which use error-prone reverse transcription to mutate target genes and may be involved in the molecular arms race between phages and their bacterial hosts.

Diazepam potentiates the antidiabetic, antistress and anxiolytic activities of metformin in type-2 diabetes mellitus with cooccurring stress in experimental animals

Psychological stress is considered as one of the limiting factors in the management of type-2 diabetes mellitus (T2DM). Therefore, the basic objective of the present study was to evaluate the antidiabetic effect of metformin, diazepam, and their combination in cooccurring T2DM and stress condition (DMS). T2DM was induced in the male rats by administering streptozotocin (45 mg/kg, i.p.) and nicotinamide (110 mg/kg, i.p.) with time lag of 15 min. Rats were subjected to two sessions of cold restraint stress paradigm for one hour on the sixth and seventh day after streptozotocin injection. Administration of metformin (25 mg/kg, p.o.) and diazepam (1 mg/kg, p.o.) in combination from the seventh to thirteenth day after streptozotocin injection showed better improvement in glucose tolerance and insulin sensitivity compared to monotherapy of either drug. In addition, the combination significantly attenuated DMS-induced hyperglycemia, hypertriglyceridaemia, hypercorticosteronemia, anxiety-like behavior, and insulin resistance through modulating insulin signaling pathway in the liver compared to monotherapy. Further, improvement of mitochondrial function, integrity, and oxidative stress in hippocampus, hypothalamus, prefrontal cortex, striatum, amygdala, and nucleus accumbens was observed with the combination. Therefore, metformin in combination with diazepam may be a better therapeutic option in the management of T2DM with cooccurring stress condition.

Homocysteine and serum lipids concentration in male war veterans with posttraumatic stress disorder

The evidence of increased cardiovascular disease (CVD) risk in posttraumatic stress disorder (PTSD) is accumulating. The present study aimed to determine whether chronic, combat-related PTSD is associated with serum lipid and homocysteine concentrations that could indicate higher CVD risk. The authors tested 66 war veterans with PTSD, 33 war veterans without PTSD, and 42 healthy volunteers for serum concentrations of homocysteine, total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and triglycerides. All the subjects were men and the analyses were adjusted for age, body mass index and smoking. Potential influences of depression, anxiety, and psychotic symptoms on the outcome measures were checked by introducing the scores from the Hamilton Depression Rating Scale (HAM-D-17), the Hamilton Anxiety Scale (HAMA), and the Positive and Negative Syndrome Scale (PANSS) into the overall statistical model. No differences in total cholesterol, LDL-C, HDL-C and triglycerides were found between the groups. Non-smoking PTSD war veterans had higher homocysteine concentrations (mean=10.4 micromol/L, SD=1.7) when compared to non-smoking war veterans without PTSD (mean=8.2 micromol/L, SD=4.0, P=0.014) and both smoking (mean=8.7 micromol/L, SD=2.3, P=0.008) and non-smoking healthy volunteers (mean=8.8 micromol/L, SD=2.2, P=0.021). The results of our cross-sectional study are possibly confounded by many factors, especially behavioral and life-style related which are difficult to control comprehensively and might have influenced serum lipids and homocysteine concentration in a complex manner. An increase in the homocysteine concentration observed in the non-smoking PTSD patients needs further investigation with a carefully designed prospective study to confirm associated, possibly enhanced CVD risk.

Diabetes: insulin resistance and derangements in lipid metabolism. Cure through intervention in fat transport and storage

We present multiple findings on derangements in lipid metabolism in type 2 diabetes. The increase in the intracellular deposition of triglycerides (TG) in muscles, liver and pancreas in subjects prone to diabetes is well documented and demonstrated to attenuate glucose metabolism by interfering with insulin signaling and insulin secretion. The obesity often associated with type 2 diabetes is mainly central, resulting in the overload of abdominal adipocytes with TG and reducing fat depot capacity to protect other tissues from utilizing a large proportion of dietary fat. In contrast to subcutaneous adipocytes, the central adipocytes exhibit a high rate of basal lipolysis and are highly sensitive to fat mobilizing hormones, but respond poorly to lipolysis restraining insulin. The enlarged visceral adipocytes are flooding the portal circulation with free fatty acids (FFA) at metabolically inappropriate time, when FFA should be oxidized, thus exposing nonadipose tissues to fat excess. This leads to ectopic TG accumulation in muscles, liver and pancreatic beta-cells, resulting in insulin resistance and beta-cell dysfunction. This situation, based on a large number of observations in humans and experimental animals, confirms that peripheral adipose tissue is closely regulated, performing a vital role of buffering fluxes of FFA in the circulation. The central adipose tissues tend to upset this balance by releasing large amounts of FFA. To reduce the excessive fat outflow from the abdominal depots and prevent the ectopic fat deposition it is important to decrease the volume of central fat stores or increase the peripheral fat stores. One possibility is to downregulate the activity of lipoprotein lipase, which is overexpressed in abdominal relatively to subcutaneous fat stores. This can be achieved by gastrointestinal bypass or gastroplasty, which decrease dietary fat absorption, or by direct means that include surgical removal of mesenteric fat. Indirect treatment consists of the compliant application of drastic lifestyle change comprising both diet and exercise and pharmacotherapy that reduces mesenteric fat mass and activity. The first step should be an attempt to effectively induce a lifestyle change. Next comes pharmacotherapy including acarbose, metformin, PPARgamma, or PPARgammaalpha agonists, statins and orlistat, estrogens in postmenopausal women or testosterone in men. Among surgical procedures, gastric bypass has been proven to produce beneficial results in advance of other surgical techniques, the evidence basis of which still needs strengthening.

Prevalence of anxiety in adults with diabetes: a systematic review

BACKGROUND

Anxiety is associated with decreased functioning and quality of life. It may have added importance in diabetes for its potential adverse effects on regimen adherence and glycemic control.

OBJECTIVE

To estimate the prevalence of clinically significant anxiety in adults with diabetes.

RESEARCH DESIGN AND METHODS

MEDLINE and PsycINFO databases and published reference lists were searched to identify studies that determined the prevalence of anxiety in diabetes from threshold scores on self-report measures or from diagnostic interviews. Prevalence was calculated as an aggregate mean weighted by the combined number of subjects in the included studies.

RESULTS

Eighteen studies having a combined population (N) of 4076 (2584 diabetic subjects, 1492 controls) satisfied the inclusion criteria. Most did not adjust for the effects of moderator variables such as gender, and only one was community-based. Generalized anxiety disorder (GAD) was present in 14% of patients with diabetes. The subsyndromal presentation of anxiety disorder not otherwise specified and of elevated anxiety symptoms were found in 27% and 40%, respectively, of patients with diabetes. The prevalence of elevated symptoms was significantly higher in women compared to men (55.3% vs. 32.9%, P<.0001) and similar in patients with Type 1 vs. Type 2 diabetes (41.3% vs. 42.2%, P=.80).

CONCLUSION

GAD is present in 14% and elevated symptoms of anxiety in 40% of patients with diabetes who participate in clinical studies. Additional epidemiological studies are needed to determine the prevalence of anxiety in the broader population of persons with diabetes.

Modulation of adipocyte lipoprotein lipase expression as a strategy for preventing or treating visceral obesity

As compared to subcutaneous adipocytes, visceral adipocytes have high basal lipolysis, are highly sensitive to catecholamines, and are poorly sensitive to insulin; these traits are amplified when visceral adipocytes hypertrophy. As a result, enlarged visceral fat stores tend to flood the portal circulation with free fatty acids at metabolically inappropriate times when fatty acids are unlikely to be oxidized, thus exposing tissues to excessive free fatty acid levels and giving rise to the insulin resistance syndrome. A logical approach to preventing or correcting visceral obesity is to down-regulate the lipoprotein lipase (LPL) activity of visceral adipocytes relative to that expressed in subcutaneous adipocytes and skeletal muscle. IGF-I activity appears to be a primary determinant of visceral LPL activity in humans; systemic IGF-I activity is decreased when diurnal insulin secretion is low, when hepatocytes detect a relative paucity of certain essential amino acids, and when estrogens are administered orally. The ability of alpha-glucosidase inhibitor therapy to selectively reduce visceral adiposity suggests that down-regulation of diurnal insulin secretion and/or IGF-I activity may indeed have a greater impact on LPL activity in visceral fat than in subcutaneous fat. Thus, low-glycemic-index, vegan, high-protein, or hypocaloric diets can be expected to decrease visceral LPL activity, as can postmenopausal estrogen therapy. Furthermore, estrogen enhances the LPL activity of non-pathogenic gluteofemoral fat cells, whereas testosterone decreases visceral LPL activity in men; this may explain why sex hormone replacement in middle-aged people of both sexes has a favorable impact on visceral fat and insulin sensitivity. Beta-adrenergic activity suppresses transcription of LPL in adipocytes; this phenomenon may contribute to the favorable impact of exercise training on visceral obesity; conceivably, preadministration of safe drugs that boost catecholamine activity (caffeine, yohimbine) could potentiate this beneficial effect of exercise. Glucocorticoids selectively increase the LPL activity of visceral adipocytes; while there is currently no convincing evidence that psychological stress is a major determinant of visceral adiposity, or that stress management techniques can help to correct visceral obesity, reports that anxiolytic therapy can improve glycemic control in type 2 diabetes should encourage further research along these lines.