Rania A. Mekary

Eating patterns and type 2 diabetes risk in men: breakfast omission, eating frequency, and snacking

BACKGROUND Little is known about the association between eating patterns and type 2 diabetes (T2D) risk. OBJECTIVE The objective of this study was to prospectively examine associations between breakfast omission, eating frequency, snacking, and T2D risk in men. DESIGN Eating patterns were assessed in 1992 in a cohort of 29,206 US men in the Health Professionals Follow-Up Study who were free of T2D, cardiovascular disease, and cancer and were followed for 16 y. We used Cox proportional hazards analysis to evaluate associations with incident T2D. RESULTS We documented 1944 T2D cases during follow-up. After adjustment for known risk factors for T2D, including BMI, men who skipped breakfast had 21% higher risk of T2D than did men who consumed breakfast (RR: 1.21; 95% CI: 1.07, 1.35). Compared with men who ate 3 times/d, men who ate 1-2 times/d had a higher risk of T2D (RR: 1.25; 95% CI: 1.08, 1.45). These findings persisted after stratification by BMI or diet quality. Additional snacks beyond the 3 main meals (breakfast, lunch, and dinner) were associated with increased T2D risk, but these associations were attenuated after adjustment for BMI. CONCLUSIONS Breakfast omission was associated with an increased risk of T2D in men even after adjustment for BMI. A direct association between snacking between meals and T2D risk was mediated by BMI.

Physical activity in relation to long-term weight maintenance after intentional weight loss in premenopausal women.

The type and amount of physical activity (PA) needed for prevention of weight regain are not well understood. We prospectively examined the associations between patterns of discretionary PA and 6‐year maintenance of intentional weight loss among 4,558 healthy premenopausal women who were 26–45 years old in 1991 and had lost >5% of their body weight in the previous 2 years. Participants reported their PA and weight in 1991 and 1997. The outcome was weight regain, defined as regaining in 1997 >30% of the lost weight between 1989 and 1991. Between 1991 and 1997, 80% of women regained >30% of their previous intentional weight loss. An increase of 30 min/day in total discretionary activity between 1991 and 1997 was associated with less weight regain (−1.36 kg, 95% confidence interval (CI) = −1.61, −1.12), particularly among overweight women (BMI ≥25) (−2.45 kg, −3.12 to −1.78). Increased jogging or running was associated with less weight regain (−3.26 kg; −4.41 to −2.10) than increased brisk walking (−1.69 kg; −2.15 to −1.22) or other activities (−1.26 kg; −1.65 to −0.87). Compared to women who remained sedentary, women were less likely to regain >30% of the lost weight if they maintained 30+ min/day of discretionary PA (odds ratio (OR) = 0.69, 0.53 to 0.89) or increased to this activity level (OR = 0.48, 0.39 to 0.60). Conversely, risk was elevated in women who decreased their activity. Increased PA, particularly high intensity activities, is associated with better maintenance of weight loss. The benefits of activity were greater among overweight/obese than normal weight women.

Physical activity patterns and prevention of weight gain in premenopausal women

Background:Studies of the association between physical activity (PA) and weight maintenance have been inconsistent.Methods:We prospectively examined the association between PA patterns and prevention of weight gain among 46 754 healthy premenopausal women, aged 25–43 years in 1989. Participants reported their PA and weight in 1989 and 1997. The primary outcome was gaining >5% of baseline weight by 1997 (62% of the population).Results:Compared with women who maintained <30 min d−1 of total discretionary activity over 8 years, women were less likely to gain weight if they sustained 30+ min d−1 (odds ratio (OR)=0.68, 95% confidence interval (CI) 0.64–0.73) or increased to 30+ min d−1 in 1997 (OR=0.64, 95%CI=0.60–0.68). Among women whose only reported activity was walking, risk of gaining weight was lower in those who sustained 30+ min d−1 over 8 years (OR=0.66, 95%CI=0.49–0.91), and brisk walking pace independently predicted less weight gain. For a 30 min d−1 increase between 1989 and 1997, jogging/running was associated with less weight gain than brisk walking or other activities. Greater duration of PA was associated with progressively less weight gain, but even an 11–20 min d−1 increase was beneficial; the benefits appeared stronger among those who were initially overweight. Sedentary behavior independently predicted weight gain.Conclusions:Sustained PA for at least 30 min d−1, particularly if more intense, is associated with a reduction in long-term weight gain, and greater duration is associated with less weight gain. Sedentary women of any baseline weight who increase their PA will benefit, but overweight women appear to benefit the most.

Sex Steroid Hormone Levels and Body Composition in Men

BACKGROUND Previous studies indicate that testosterone (T) is positively correlated with lean mass and inversely correlated with fat mass in men; however, the directionality of these associations, as well as the association with other hormones including estradiol (E2) and SHBG, is unclear. METHODS We examined cross-sectional and longitudinal associations of E2, T, SHBG, and E2/T ratio with body composition among men ages 30 to 79 in the Boston Area Community Health/Bone Survey. Total, trunk, and appendicular lean and fat mass were measured by dual-energy x-ray absorptiometry at baseline, and weight and waist/hip circumference were measured at baseline and follow-up. Partial Pearson correlation coefficients were used to estimate the linear relationship between each body composition measure and log-transformed hormone variable. RESULTS In cross-sectional analyses of 821 men, T, calculated free T, and SHBG were inversely correlated with fat mass, weight, body mass index, waist/hip circumference, and waist-to-hip ratio, with multivariable-adjusted correlations ranging from -0.13 to -0.37. Calculated free E2 was positively correlated with percentage total (r = .13) and trunk (r = .15) fat mass, and E2/T was positively correlated with all measures examined (r = .13-.40). There were no significant multivariable-adjusted longitudinal associations between baseline hormone levels and change in weight, body mass index, waist/hip circumference, or waist-to-hip ratio after an average follow-up of 4.8 years. CONCLUSIONS We observed significant cross-sectional associations between hormone levels, including E2, T, and E2/T, and body composition measures in men. Longitudinal analyses showing no influence of baseline hormone levels on change in anthropometric measures imply that body composition affects hormone levels and not the reverse.

Weight training, aerobic physical activities, and long-term waist circumference change in men.

Findings on weight training and waist circumference (WC) change are controversial. This study examined prospectively whether weight training, moderate to vigorous aerobic activity (MVAA), and replacement of one activity for another were associated with favorable changes in WC and body weight (BW).

Strength Training Prevents Hyperinsulinemia, Insulin Resistance, and Inflammation Independent of Weight Loss in Fructose-Fed Animals.

The aim of this study was to compare the effects of aerobic, strength, and combined training on metabolic disorders induced by a fructose-rich diet. Wistar rats (120 days old) were randomized into five groups (n = 8–14): C (control diet and sedentary), F (fed the fructose-rich diet and sedentary), FA (fed the fructose-rich diet and subject to aerobic exercise), FS (fed the fructose-rich diet and subject to strength exercise), and FAS (fed the fructose-rich diet and subject to combined aerobic and strength exercises). After the 8-week experiment, glucose homeostasis, blood biochemistry, tissue triglycerides, and inflammation were evaluated and analyzed. The strength protocol exerted greater effects on glucose homeostasis, insulin sensitivity, and liver lipid contents than other protocols (all P < 0.05). All three exercise protocols induced a remarkable reduction in inflammation, tissue triglyceride content, and inflammatory pathways, which was achieved through c-Jun NH2-terminal kinase (JNK) phosphorylation and factor nuclear kappa B (NFkB) activation in both the liver and the muscle. Our data suggest that strength training reduced the severity of most of the metabolic disorders induced by a fructose-rich diet and could be the most effective strategy to prevent or treat fructose-induced metabolic diseases.

Predictors and Rates of Delayed Symptomatic Hyponatremia after Transsphenoidal Surgery: A Systemastic Review

BACKGROUND Delayed symptomatic hyponatremia (DSH) is a known complication of transsphenoidal surgery that can lead to prolonged hospital stay, readmission, and in rare cases, death. Many potential predictors for development of DSH have been investigated. A better understanding of DSH risk can lead to better patient outcomes. We performed a systematic review to determine the rates and predictors of DSH after both endoscopic transsphenoidal surgery and microscopic transsphenoidal surgery. METHODS A systematic search of the literature was conducted using MEDLINE/PUBMED, EMBASE, and Cochrane databases. Inclusion criteria were 1) case series with at least 10 cases reported, 2) adult patients who underwent eTSS or mTSS for pituitary tumors, and 3) reported occurrence of DSH (defined as serum sodium level <135 mEq/L with associated symptoms) after postoperative day 3. Data were analyzed using CMA V.3 Statistical Software (2014). RESULTS Ten case series satisfied the inclusion criteria for a total of 2947 patients. Various factors including age, gender, cerebrospinal fluid leak, and tumor size were investigated as potential predictors of DSH. DSH event rates for both mTSS and eTSS fell between around 4 and 12 percent and included a variety of proposed predictors. CONCLUSIONS Age, gender, tumor size, rate of decline of blood sodium, and Cushing disease are potential predictors of DSH. By identifying patients at high risk for DSH, preventative efforts can be implemented in the perioperative setting to reduce the incidence of potentially catastrophic hyponatremia following transsphenoidal surgery.

The Joint Association of Eating Frequency and Diet Quality With Colorectal Cancer Risk in the Health Professionals Follow-up Study

The results of most case-control studies have suggested a positive association between eating frequency and colorectal cancer risk. Because no prospective cohort studies have done so to date, the authors prospectively examined this association. In 1992, eating frequency was assessed in a cohort of 34,968 US men in the Health Professionals Follow-up Study. Cox proportional hazards regression models were used to estimate relative risks and 95% confidence intervals for various levels of eating frequency. Effect modifications by overall dietary quality (assessed using the Diet Approaches to Stop Hypertension score) and by factors that influence insulin resistance were further assessed. Between 1992 and 2006, a total of 583 cases of colorectal cancer were diagnosed. When comparing the highest eating frequency category (5-8 times/day) with the reference category (3 times/day), the authors found no evidence of an increased risk of colorectal cancer (multivariate relative risk = 0.88, 95% confidence interval: 0.62, 1.26) or colon cancer (multivariate relative risk = 0.78, 95% confidence interval: 0.49, 1.25). There was an implied inverse association with eating frequency among participants who had healthier diets (high Diet Approaches to Stop Hypertension score; P for interaction = 0.01), especially among men in the high-insulin-sensitivity group (body mass index (weight (kg)/height (m)(2)) <25, ≥2 cups of coffee/day, and more physical activity; P for interaction < 0.01, P for trend = 0.01). There was an implied protective association between increased eating frequency of healthy meals and colorectal cancer risk and in men with factors associated with higher insulin sensitivity.

Venous thromboembolism prophylaxis in brain tumor patients undergoing craniotomy: a meta-analysis

Brain tumor patients undergoing craniotomy generally receive prophylaxis against venous thromboembolism (VTE), but modalities in use differ widely and have been debated in the literature. A systematic review and meta-analysis was conducted to assess the efficacy and safety of VTE prophylaxis among brain tumor patients undergoing craniotomy. Ten randomized controlled trials were included in the final efficacy analysis. The various prophylactic measures employed in these studies reduced the risk for thrombosis compared to controls with an overall risk ratio of 0.61 (95 % CI: 0.47–0.79) in the fixed effect model. Although Cochrane Q-test showed unimportant heterogeneity across studies (p = 0.19) and the I2, a measure of heterogeneity between studies, was reasonably low at 28 %, subgroup analysis indicated that intervention type was a potential effect modifier for efficacy (p = 0.04). Unfractionated heparin alone showed a stronger reduction in VTE risk compared to placebo (RR = 0.27; 95 % CI: 0.10–0.73), and LMWH combined with mechanical prophylaxis showed a lower VTE risk as compared to mechanical prophylaxis alone (0.61; 95 % CI: 0.46–0.82). This meta-analysis demonstrates a statistically significant VTE risk reduction among brain tumor patients receiving prophylaxis, with chemical prophylaxis showing the strongest risk reduction. Five studies were included in the safety analysis, which showed an overall increased risk of bleeding comparing different prophylactic measures to different controls (RR = 2.02; 95 % CI: 1.14–3.58; I2 = 0 %; p = 0.86). Interventions in these studies were associated with an increased risk of post-operative, minor hemorrhage (RR = 2.20; 95 % CI = 1.00; 4.85), while the risk of major hemorrhage was not increased by chemoprophylaxis.

Fructose Consumption in the Development of Obesity and the Effects of Different Protocols of Physical Exercise on the Hepatic Metabolism

Fructose consumption has been growing exponentially and, concomitant with this, the increase in the incidence of obesity and associated complications has followed the same behavior. Studies indicate that fructose may be a carbohydrate with greater obesogenic potential than other sugars. In this context, the liver seems to be a key organ for understanding the deleterious health effects promoted by fructose consumption. Fructose promotes complications in glucose metabolism, accumulation of triacylglycerol in the hepatocytes, and alterations in the lipid profile, which, associated with an inflammatory response and alterations in the redox state, will imply a systemic picture of insulin resistance. However, physical exercise has been indicated for the treatment of several chronic diseases. In this review, we show how each exercise protocol (aerobic, strength, or a combination of both) promote improvements in the obesogenic state created by fructose consumption as an improvement in the serum and liver lipid profile (high-density lipoprotein (HDL) increase and decrease triglyceride (TG) and low-density lipoprotein (LDL) levels) and a reduction of markers of inflammation caused by an excess of fructose. Therefore, it is concluded that the practice of aerobic physical exercise, strength training, or a combination of both is essential for attenuating the complications developed by the consumption of fructose.