Targeted peripheral focused ultrasound stimulation attenuates obesity-induced metabolic and inflammatory dysfunctions.

Obesity, a growing health concern, is associated with an increased risk of morbidity and mortality. Chronic low-grade inflammation is implicated in obesity-driven metabolic complications. Peripheral focused ultrasound stimulation (pFUS) is an emerging non-invasive technology that modulates inflammation. Here, we reasoned that focused ultrasound stimulation of the liver may alleviate obesity-related inflammation and other comorbidities. After 8 weeks on a high-fat high-carbohydrate "Western" diet, C57BL/6J mice were subjected to either sham stimulation or focused ultrasound stimulation at the porta hepatis. Daily liver-focused ultrasound stimulation for 8 weeks significantly decreased body weight, circulating lipids and mitigated dysregulation of adipokines. In addition, liver-focused ultrasound stimulation significantly reduced hepatic cytokine levels and leukocyte infiltration. Our findings demonstrate the efficacy of hepatic focused ultrasound for alleviating obesity and obesity-associated complications in mice. These findings suggest a previously unrecognized potential of hepatic focused ultrasound as a possible novel noninvasive approach in the context of obesity.

Ultrasound Evaluation of a Single Treatment With a Temperature Controlled Multi-Frequency Monopolar Radio Frequency Device for the Improvement of Localized Adiposity on the Abdomen and Flanks

BACKGROUND AND OBJECTIVES: Energy modalities used for fat reduction include cryotherapy, focused and unfocused ultrasound, radiofrequency, and laser. Two devices have been proven to reduce fat layer thickness using ultrasound as measurement after a single treatment. We hypothesized that a novel, high frequency monopolar radiofrequency device could increase the fat temperature enough to reduce its thickness as measured by ultrasound, without excessively increasing the temperature of the skin, leading to a safe, tolerable, and clinically relevant reduction of fat. STUDY DESIGN/MATERIALS AND METHODS: A high frequency monopolar radiofrequency platform was used to treat twelve patients on the abdomen or flanks (truSculpt® 3D, Cutera, Brisbane, CA). Each patient received one treatment session, consisting of 15-minute increments for four areas (60 minutes total). Each area (approximately 144 cm2) was treated with a gliding handpiece technique to a skin temperature of 44-45˚C, correlating to in vivo measurements of the subcutaneous layer of >45˚C. Patients were evaluated at eight- and twelve-weeks following treatment. Clinical efficacy was measured using 360˚ positioned clinical photography. Fat layer reduction was measured with ultrasound. Safety was assessed by the treating physician; patient comfort was assessed during treatment via a 10-point pain scale. RESULTS: All patients responded to treatment. Ultrasound measurements indicated mean fat layer reduction of 4.6 mm, which correlated with a 24% reduction in fat layer thickness at 12 weeks. A significant improvement was noted between the 8-week and the 12-week follow up. A high level of inter-patient consistency was achieved with most patients (10/12= 83%) having an average fat thickness reduction of >20%. No adverse events were observed, and pain scores during the treatment session ranged from 2 to 4 out of 10. CONCLUSION: High frequency monopolar radiofrequency device produced consistent and statistically significant fat thickness reduction from a single 60-minute treatment session, with minimal discomfort and no demonstrated side effects. Results are comparable to other hypo- and hyper-thermic fat treatment technologies. KEY WORDS: fat reduction, radiofrequency, monopolar RF, fat thickness reduction, body sculpting J Drugs Dermatol. 2020;19(1):28-34. doi:10.36849/JDD.2020.4568

Low-dose UV radiation before running wheel access activates brown adipose tissue.

In previous preclinical studies, low (non-burning) doses of UV radiation (UVR) limited weight gain and metabolic dysfunction in mice fed with a high-fat diet. Here, we explored the effects of low-dose UVR on physical activity and food intake and mechanistic pathways in interscapular brown adipose tissue (iBAT). Young adult C57Bl/6J male mice, housed as individuals, were fed a high-fat diet and exposed to low-dose UVR (sub-oedemal, 1 kJ/m2 UVB, twice-a-week) or 'mock' treatment, with or without running wheel access (2 h, for 'moderate' physical activity) immediately after phototherapy. There was no difference in distance run in mice exposed to UVR or mock-treated over 12 weeks of exposure to running wheels (P = 0.14). UVR (alone) did not significantly affect food intake, adiposity, or signs of glucose dysfunction. Access to running wheels increased food intake (after 10 weeks, P ≤ 0.02) and reduced gonadal white adipose tissue and iBAT mass (P ≤ 0.03). Body weight and hepatic steatosis were lowest in mice exposed to UVR with running wheel access. In the iBAT of mice exposed to UVR and running wheels, elevated Atgl, Cd36, Fasn, Igf1, Pparγ, and Ucp1 mRNAs and reduced CD11c on F4-80 + MHC class II+ macrophages were observed, while renal Sglt2 mRNA levels were increased, compared to high-fat diet alone (P ≤ 0.03). Blood levels of 25-hydroxyvitamin D were not increased by exposure to UVR and/or access to running wheels. In conclusion, when combined with physical activity, low-dose UVR may more effectively limit adiposity (specifically, body weight and hepatic steatosis) and modulate metabolic and immune pathways in iBAT.

Effect of four sessions of aerobic exercise with abdominal radiofrequency in adipose tissue in healthy women: Randomized control trial.

BACKGROUND: Abdominal adiposity is a cardiovascular risk factor; it is assumed that the combination of radiofrequency and physical exercise may decrease this excess of adipose tissue. PURPOSE: To analyze the effect of four intervention sessions on abdominal adipose tissue. METHODOLOGY: The study analyzes the effect of four sessions of aerobic exercise combined with radiofrequency. Participants were 28 healthy female volunteers, aged 18-28 years, randomly assigned to an experimental group and a placebo group. They were characterized by a sociodemographic questionnaire, the International Physical Activity Questionnaire and the Food Frequency Questionnaire. The groups performed four sessions of abdominal radiofrequency followed by moderate aerobic exercise, assessing body mass, body mass index, fat mass, waist circumference, waist/height ratio, subcutaneous adipose thickness, and horizontal abdominal adipose fold at the first and fourth sessions. In the experimental group, a percentage of potency was used that allowed to maintain the temperature between 40°C and 42°C to the epidermis. In the placebo group, the power of the radiofrequency was 0 W. To compare results, Student's t test was used for a significance level of 0.05. RESULTS: There was a statistically significant decrease in waist circumference, abdominal subcutaneous adipose thickness, and horizontal abdominal fold in the experimental group compared to the placebo group (P < 0.05). CONCLUSION: Combined exercise intervention with radiofrequency has been shown to be effective in reducing abdominal adiposity.

Phase Angle as an Objective and Predictive Factor of Radiotherapy-induced Changes in Body Composition of Male Patients With Head and Neck Cancer.

BACKGROUND: Unfavorable changes in body composition are frequent among patients with head and neck cancer (HNC). Unfortunately, in daily clinical practice, there is a lack of reliable diagnostic tools for predicting changes in body composition in individuals following radiotherapy (RT). Among non-invasive tools, bioelectrical impedance analysis (BIA) seems to be most promising. One BIA parameter, the phase angle (PA), reflects condition of various body cells and their mass in detail. MATERIALS AND METHODS: Using BIA, the body composition was measured prior to and after RT in 52 male patients with HNC. PA derived from BIA prior to RT was tested as a predictor of body composition changes developing during RT. RESULTS: Patients with low PA had a greater than 9.3-fold higher chance of body mass index (BMI) reduction below 18.5 kg/m2 and over 5.9-fold and 4.2-fold higher chance of lean mass and fat mass reduction after therapy end compared with patients with a high PA value. PA values demonstrated significant diagnostic accuracy for detection of fat-free mass, lean mass and BMI reduction in the study group [area under the curve (AUC)=0.781, 0.774 and 0.786, respectively]. CONCLUSION: PA prior to RT is a useful marker for selection of individuals with HNC who are at a high risk of unfavorable changes in body composition.

Leptin level decreases after treatment with the combination of Radiofrequency and Ultrasound cavitation in response to the reduction in adiposity.

BACKGROUND: Obesity and overweight are major public health problem. Different-strategies have been developed for body contouring including Radiofrequency(RF) and Ultrasound(US). The aim of this study was to investigate changes in serum-leptin as a potential-modulator of food/energy intake, in overweight-women receiving RF/US and diet-therapy as well as the effect of therapy on modulation of lipid-profile and body-fat-mass. METHODS: Fifty overweight-females were enrolled in current randomized-clinical-trial and randomly divided into two groups. The case group received RF/US twice a week for 5 weeks with a low calorie diet whilst the control-group received just a low calorie diet. Demographic, biochemical markers as well as serum-leptin were determined. RESULTS: The level of leptin was reduced from 1.29 ±â€¯0.32 ng/ml to 1.14 ±â€¯0.34 ng/ml in case group, before and after therapy, respectively, whilst no significant differences were observed in the serum leptin levels of subjects in the control group. The combination of RF and US decreased the leptin-level. In particular, the mean reduction of abdominal-circumference and waist-circumference was significant (P < 0.05) after therapy. This reduction was inversely correlated with LDL levels. Weight was reduced in case and control groups and in both was significant, but no statistically significant differences were detected for weight between the groups(P < 0.93). CONCLUSION: Our findings demonstrated the reduction of the leptin after treatment with the combination of Radiofrequency/Ultrasound cavitation, which was associated with reduced body-fat-mass.

Exposure to solar ultraviolet radiation limits diet-induced weight gain, increases liver triglycerides and prevents the early signs of cardiovascular disease in mice.

BACKGROUND AND AIMS: Sunlight exposure is associated with a number of health benefits including protecting us from autoimmunity, cardiovascular disease, obesity and diabetes. Animal studies have confirmed that ultraviolet (UV)-B radiation, independently of vitamin D, can limit diet-induced obesity, metabolic syndrome and atherosclerosis. The aim of this study is to investigate whether exposure to the UV radiation contained in sunlight impacts on these disease parameters. METHODS AND RESULTS: We have trialled an intervention with solar UV in obese and atherosclerosis-prone mice. We have discovered that solar-simulated UV can significantly limit diet-induced obesity and reduce atheroma development in mice fed a diet high in sugar and fat. The optimal regime for this benefit was exposure once a week to solar UV equivalent to approximately 30 min of summer sun. Exposure to this optimal dose of solar UV also led to a significant increase in liver triglycerides which may protect the liver from damage. CONCLUSION: Our results show that the UV contained in sunlight has the potential to prevent and treat chronic disease at sites distant from irradiated skin. A major health challenge going forward will be to harness the power of the sun safely, without risking an increase in skin cancers.

Regular exposure to non-burning ultraviolet radiation reduces signs of non-alcoholic fatty liver disease in mature adult mice fed a high fat diet: results of a pilot study.

OBJECTIVE: Obesity often emerges in middle age, increasing risk for metabolic disorders. Our previous preclinical experiments identified that chronic exposure to non-burning ultraviolet radiation, like that achieved through sun exposure, prevented weight gain and signs of metabolic dysfunction in young adult mice fed a high fat diet. Our objective was to perform a pilot study to estimate the effect size of ongoing exposure to sub-erythemal (non-burning, low dose) UVB (1 kJ/m2) radiation on measures of adiposity, food intake and physical activity in 'mature' adult C57Bl/6J male mice fed a high fat diet for 12 weeks. RESULTS: The severity of liver steatosis, fibrosis and inflammation were reduced in older adult mice exposed twice a week to ultraviolet radiation (from 29 weeks of age), compared to mock-irradiated mice, with some evidence for reduced hepatic mRNAs for tnf and tgfß1 (not fatp2 nor fasN). Power analyses suggested that up to 24 mice per treatment would be required in future experiments to detect a significant effect on some markers of adiposity such as body weight gain. Our studies suggest frequent exposure to low levels of sunlight may reduce the severity of hepatic steatosis induced in older adults living in environments of high caloric intake.

Infrared photobiomodulation (PBM) therapy improves glucose metabolism and intracellular insulin pathway in adipose tissue of high-fat fed mice.

Obesity represents a continuously growing global epidemic and is associated with the development of type 2 diabetes mellitus. The etiology of type 2 diabetes is related to the resistance of insulin-sensitive tissues to its action leading to impaired blood glucose regulation. Photobiomodulation (PBM) therapy might be a non-pharmacological, non-invasive strategy to improve insulin resistance. It has been reported that PBM therapy in combination with physical exercise reduces insulin resistance. Therefore, the aim of this study was to investigate the effects of PBM therapy on insulin resistance in obese mice. Male Swiss albino mice received low-fat control diet (n = 16, LFC) or high-fat diet (n = 18, HFD) for 12 weeks. From 9th to 12th week, the mice received PBM therapy (LASER) or Sham (light off) treatment and were allocated into four groups: LFC Sham (n = 8), LFC PBM (n = 8), HFD Sham (n = 9), and HFD PBM (n = 9). The PBM therapy was applied in five locations: to the left and right quadriceps muscle, upper limbs and center of the abdomen, during 40 s at each point, once a day, 5 days a week, for 4 weeks (780 nm, 250 mW/cm2, 10 J/cm2, 0.4 J per site; 2 J total dose per day). Insulin signaling pathway was evaluated in the epididymal adipose tissue. PBM therapy improved glucose tolerance and phosphorylation of Akt (Ser473) and reversed the HFD-induced reduction of GLUT4 content and phosphorylation of AS160 (Ser588). Also, PBM therapy reversed the increased area of epididymal and mesenteric adipocytes. The results showed that chronic PBM therapy improved parameters related to obesity and insulin resistance in HFD-induced obesity in mice.

Sub-erythemal ultraviolet radiation reduces metabolic dysfunction in already overweight mice.

Exposure to sunlight may limit cardiometabolic risk. In our previous studies, regular exposure to sub-erythemal (non-burning) ultraviolet radiation (UVR) reduced signs of adiposity and cardiometabolic dysfunction in mice fed a high-fat diet. Some of the observed effects were dependent on skin release of nitric oxide after UVR exposure. Here, we examine the effects of sub-erythemal UVR on signs of adiposity and metabolic dysfunction in already overweight mice, comparing the effects of two sunlamps with distinct emitted light spectra. Mice were fed a high-fat diet from 8 weeks of age, with UVR administered twice a week from 14 weeks of age until they were killed at 20 weeks of age. Mice were irradiated with the same dose of UVB radiation (1 kJ/m2) from either FS40 (65% UVB, 35% UVA) or CLEO (4% UVB, 96% UVA) sunlamps, but substantially more UVA from the latter. FS40 UVR (but not CLEO UVR) significantly reduced mouse weights and weight gain, compared to mice fed a high-fat diet (only). These effects were dependent on nitric oxide. Conversely, CLEO UVR (but not FS40 UVR) significantly reduced circulating LDL cholesterol. Both light sources reduced fasting insulin levels, and the extent of hepatic steatosis; the latter was reversed by topical application of cPTIO, suggesting an important role for skin release of nitric oxide in preventing hepatic lipid accumulation. These results suggest that there may be a number of benefits achieved by regular exposure to safe (non-burning) levels of sunlight or UV-containing phototherapy, with effects potentially dependent on the predominance of the wavelengths of UVR administered.

Escala colorimétrica del porcentaje de grasa corporal según el estimador de adiposidad CUN-BAE / Colour scale percent body fat by CUN-BAE adiposity estimator

No disponible

Redistribution of body composition in patients with Graves' disease after iodine-131 treatment.

OBJECTIVE: The objective of this study was to investigate body composition redistribution at 3 months after radioactive iodine therapy (RAI). METHODS: Eighty patients with Graves' disease (GD) for RAI and 18 volunteers were recruited. All patients underwent thyroid status test and dual-energy x-ray absorptiometry at baseline and 3 months after RAI. According to the second thyroid status test, patients were divided into the following groups: A, with aggravated hyperthyroidism; B-1, with improved hyperthyroidism; B-2, with euthyroidism; and B-3, with hypothyroidism. RESULTS: Total lean mass (LM) but fat mass (FM) and bone mineral content (BMC) of whole GD patients after RAI recovered to be not different with controls. Compared with baseline, in group A, FM in the left leg increased, and LM in left arm, right arm, trunk and total LM decreased (P<0.05). In B-2, FM in the head increased, and LM in the head, right arm, trunk and total LM increased (P<0.05). In B-3, FM in the right leg and total body fat percentage decreased, but FM in the head, android-to-gynoid fat ratio and body mass index increased (P<0.05); LM of all sites, weight and total mass increased (P<0.05); BMC in lumbar spine and left leg, and total BMC decreased (P<0.05). Body composition of unmentioned sites was retained after RAI in each group (P>0.05). CONCLUSIONS: Replenishment of LM gets priority rather than FM and BMC during the first 3 months after RAI, and the increase in LM starts from the upper body; head is the regional site in which FM recovery occurs first.

Evaluation of ultrasound combined with chitosan for the control of weight and local fat in mice.

Ultrasound (US) has recently been used to reduce localized adiposity in humans. The study described here evaluated the combined use of chitosan, which is used to treat hyperlipidemic diseases and fatty liver, and US to control weight and local fat deposition in normal mice over a 5-wk experimental period. Female ICR mice were randomly divided into four groups (n = 5 animals per group): (1) control, (2) US only, (3) chitosan only and (4) chitosan + US. Body weight, epididymal fat pad and intra-abdominal fat thickness (via US imaging) and plasma concentrations of high-density lipoprotein cholesterol, triglycerides and low-density lipoprotein cholesterol were measured in all mice before and after the 5-wk treatment period. After the 5-wk treatment period, weight had decreased significantly in the chitosan + US group (-11.2%) compared with the US only (-5.8%) and chitosan only (-9.3%) groups (p < 0.05). The reduction in epididymal fat pad thickness was significantly more marked in the chitosan + US group (28.2%) than in the other groups (p < 0.05). Furthermore, in the chitosan + US group, plasma levels of triglycerides and low-density lipoprotein cholesterol significantly decreased by 51.5% and 26%, respectively. This is the first report of effective control of weight and local fat by a combination of ultrasound and a putative fat-reducing dietary supplement in mice. The described method significantly decreases local fat pad deposition, weight and plasma lipid levels.

Cranial radiotherapy predisposes to abdominal adiposity in survivors of childhood acute lymphocytic leukemia.

BACKGROUND: Advances in treatment of acute lymphocytic leukemia increased the likelihood of developing late treatment-associated effects, such as abdominal adiposity, increasing the risk of cardiovascular disease in this population. Cranial radiotherapy is one of the factors that might be involved in this process. The aim of this study was to determine the effect of cranial radiotherapy on adiposity indexes in survivors of acute lymphocytic leukemia. METHODS: A comparative cross-sectional study of 56 acute lymphocytic leukemia survivors, chronological age between 15 and 24 years, assigned into two groups according to the exposure to cranial radiotherapy (25 irradiated and 31 non-irradiated), assessed according to body fat (dual energy X-ray absorptiometry), computed tomography scan-derived abdominal adipose tissue, lipid profile, and insulin resistance. RESULTS: Cranial radiotherapy increased body fat and abdominal adipose tissue and altered lipid panel. Yet, lipids showed no clinical relevance so far. There were significantly more obese patients among those who received cranial radiotherapy (52% irradiated versus 22.6% non-irradiated), based on dual energy X-ray absorptiometry body fat measurements. Nonetheless, no association was observed between cranial radiotherapy and body mass index, waist circumference, waist-to-height ratio or insulin resistance. CONCLUSIONS: Adolescent and young adult survivors of childhood acute lymphocytic leukemia showed an increase in body fat and an alteration of fat distribution, which were related to cranial radiotherapy. Fat compartment modifications possibly indicate a disease of adipose tissue, and cranial radiotherapy imports in this process.

Independent evaluation of low-level laser therapy at 635 nm for non-invasive body contouring of the waist, hips, and thighs.

INTRODUCTION: The non-invasive body-contouring segment continues to exhibit uninhibited growth, a trend that has provoked the emergence of numerous body-contouring devices. One particular device, low-level laser therapy at 635 nm (LLLT-635), has exhibited promising clinical results. We performed an independent, physician-led trial to evaluate the utility of LLLT-635 nm for non-invasive body contouring of the waist, hips, and thighs. METHODS: Eighty-six participants were retrospectively assessed at an individual clinic in the United States. A multi-head laser device was administered every-other-day for 2 weeks. Each treatment consisted of 20 minutes of anterior and posterior treatment. Patients received concurrent treatment of the waist, hips, and bilateral thighs. Circumferential measurements were evaluated at baseline and one week following the 2-week treatment administration phase. RESULTS: Compared with baseline, a statistically significant 2.99 in. (7.59 cm) mean loss was observed at the post-procedure evaluation point (P < 0.0001). When analyzed individually, the waist, hips, and thighs each reported a statistically significant reduction of -1.12, -0.769, and -1.17, respectively. Furthermore, linear regression analysis revealed a weak linear dependence (r = 0.179) between the reported weight and circumference change. CONCLUSION: These data further validate the clinical efficacy and safety of LLLT at 635 nm.

[The analysis of a diet food of the persons working with sources of an ionizing radiation in Moscow and Moscow region].

An actual food, including a food represented at the enterprise to workers, contacting to ionizing radiation sources is analysed. The considerable contribution of a treatment-and-prophylactic food to food and power value of a diet is established. It is revealed that the majority of the surveyed persons eat with infringement of principles of a balanced diet. It is established that an actual food of the surveyed contingent includes the elements which are risk factors of development of cardiovascular diseases, diabetes, etc. metabolism diseases. Prevalence of superfluous weight of a body and adiposity aged is more senior 40 years has made 70%. A treatment-and-prophylactic food demands correction, working out approximate 7-10 day menus is necessary.

Adiposity in female B6C3F1 mice continuously irradiated with low-dose-rate gamma rays.

Abstract We previously reported significant increases in body weight in B6C3F1 mice continuously exposed to low-dose-rate (21 mGy/day) gamma rays compared to that of nonirradiated control mice (Tanaka et al., Radiat. Res. 167, 417-437, 2007). To further study the underlying cause of the increase in body weight, feed consumption, adipose tissue weight, liver and serum lipid contents, and selected factors related to glucose and lipid metabolism such as serum levels of insulin and adipocytokines were examined in female B6C3F1 mice irradiated continuously with gamma rays at 20 mGy/day in group-housed or individually housed rearing conditions. Increased body weight, adipose tissue weight, serum levels of leptin, and lipid contents of the liver and serum were observed in both group-housed (accumulated dose = 6 Gy, 43 weeks from start of irradiation) and individually housed (accumulated dose = 4.4 Gy, 31 weeks from start of irradiation) irradiated mice compared to nonirradiated controls. Feed consumption measurements, however, revealed no significant difference between irradiated mice and nonirradiated controls when mice were housed individually. Our results show for the first time that the increase in the body weight of mice continuously irradiated with low-dose-rate gamma rays is due to adiposity with no corresponding increase in feed consumption.

Constant light induces alterations in melatonin levels, food intake, feed efficiency, visceral adiposity, and circadian rhythms in rats.

Melatonin levels, metabolic parameters, circadian rhythm activity patterns, and behavior were observed in rats subjected to a 12-h/12-h light/dark cycle (LD) compared to animals exposed to continuous dark (DD) or continuous light (LL). LD and DD animals were similar in melatonin levels, food intake, relative food intake, feed efficiency, water intake, circadian activity levels, and behavior. LL animals had lower melatonin levels in the subjective dark compared to LD and DD animals. Food intake, relative food intake, and water intake values were lower and feed efficiency was more positive in LL animals compared to LD and DD animals. In addition, LL animals exhibited greater visceral adiposity than the other two groups. The circadian rhythmicity of activity became free-running in LL animals and there was a decrease in overall activity. Notable behavioral changes in LL animals were an increase in irritability and excitability. Results indicate that a decrease in melatonin levels and concomitant changes in metabolism, circadian rhythms, and behavior are consequences of exposure to constant light.

Short day-length increases sucrose consumption and adiposity in rats fed a high-fat diet.

BACKGROUND: Photoperiod, i.e., the relative day-length per 24h, may modulate the metabolic responses to high-fat diet (HFD) and sucrose consumption. METHODS: To test this hypothesis, hormonal changes, fat accretion and sucrose intake were measured in rats exposed to short- or long-day for 4 weeks and fed with a standard high-carbohydrate low-fat pelleted diet (high-carbohydrate diet (HCD)) or a high-fat, medium-carbohydrate pelleted diet (HFD), with or without free access to 10% sucrose solution in addition to water available ad libitum. RESULTS: Plasma leptin and adiposity index, defined as epididymal white fat expressed as percentage of body mass, were markedly increased only in HFD-fed animals drinking sucrose under short, but not long, photoperiods. Voluntary ingestion of sucrose under short days was greater in HFD rats compared with HCD animals over the experiment, while a trend for the opposite effect was visible under long days. Total energy intake was not changed overall, as rats proportionally decreased chow intake when they drank sucrose. A noteworthy exception was the HFD group with sucrose access under short days that significantly increased their total calorie intake. Fasting blood glucose was generally unaltered, except for an increase in HFD-fed animals drinking sucrose under long days compared to control animals, suggesting a decrease in glucose tolerance. Insulin resistance was not yet affected by nutritional or photoperiodic conditions after 4 experimental weeks. CONCLUSIONS: Even if photoperiod cannot be considered as an obesogenic environmental factor per se, the metabolic effects resulting from the combination of high-fat feeding and voluntary intake of sucrose were dependent on day-length. Exposure to short days triggers a larger increase of sucrose ingestion and hyperleptinemia in rats fed with HFD compared to the control diet. Considering that the cardinal symptoms of winter depression include carbohydrate craving and increased adiposity, the present data provide an experimental basis for developing new animal models of seasonal affective disorder.

Reduced adiposity in ob/ob mice following total body irradiation and bone marrow transplantation.

OBJECTIVE: The objective of this study was to assess long-term metabolic consequences of total body irradiation (TBI) and bone marrow transplantation. Severe obesity develops due to both hypertrophy and hyperplasia of adipocytes. We hypothesized that TBI would arrest adipose tissue growth and would affect insulin resistance (IR). RESEARCH METHODS AND PROCEDURES: We exposed 2-month-old female ob/ob mice to 8 Grays of TBI followed by bone marrow transplantation and tested the animals for body weight (BW) gain, body composition, blood glucose, and insulin sensitivity. RESULTS: Two months after TBI, irradiated mice stopped gaining BW, whereas non-treated mice continued to grow. At the age of 9.5 months, body mass of irradiated mice was 60.6 +/- 1.4 grams, which was only 61% of that in non-treated ob/ob controls (99.4 +/- 1.6 grams). Body composition measurements by DXA showed that decreased BW was primarily due to an impaired fat accumulation. This could not result from the production of leptin by bone marrow-derived adipocyte progenitors because inhibition of the obese phenotype was identical in recipients of both B6 and ob/ob bone marrow. Inability of the irradiated mice to accumulate fat was associated with hepatomegaly, lower levels of monocyte chemoattractant protein-1 expression in adipose tissue, and increased IR. DISCUSSION: Our data argue in favor of the hypothesis that inability of adipose tissue to expand may increase IR. This mouse model may be valuable for studies of late-onset radiation-induced IR in humans.