Risk Factors for COVID-19: Diabetes, Hypertension, and Obesity.

INTRODUCTION: The recent global pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has involved more than 7 million people worldwide and been associated with more than 400,000 deaths. No clear information is known about all the potential risk factors for COVID-19 or what factors adversely influence its clinical course and mortality. Therefore, we analyzed the role of obesity, type 2 diabetes, and hypertension as risk factors for COVID-19. METHODS: We identified articles for inclusion by searching PubMed and Google Scholar (last accessed 15 June 2020). Retrospective review of literature. Analysis of epidemiological data concerning obesity prevalence and COVID-19 incidence, particularly in Italy and the USA. RESULTS: Data from several retrospective studies of prevalence showed that patients with hypertension, type 2 diabetes, and obesity may have more severe COVID-19, intensive care unit admission, and higher mortality rates, but it is not definitively clear if this is an independent association. In general, the prevalence of obesity in patients with COVID-19 seems to be the same as that of the general population throughout the world; however, obesity seems to be associated with more severe disease and mortality in younger (< 60 years) patients. Similar effects seem to occur in patients with diabetes and/or hypertension but at older ages (> 60 years). In strict connection, it has been proposed that the use of drugs inhibiting angiotensin-converting enzyme 2 (ACE-2) or dipeptidyl dipeptidase 4 (DPP-4) might influence viral activity and disease severity since ACE-2 and DPP-4 receptors mediate SARS-CoV-2 entry into the host cells; however, no evidence exists to date that shows that this may be the case. CONCLUSION: Overall, diabetes, hypertension, and obesity seem to negatively affect the clinical course and disease outcome in patients with COVID-19. However, these data need further confirmation by studies with more accurate data registration.

Serum Irisin Concentrations in Severely Inflamed Patients.

Irisin is a recently discovered exercise-induced myokine that has been attributed the role of favoring white-to-brown adipose tissue trans-differentiation. We confirmed in a population-based cohort that irisin serum concentrations are independently correlated with the habitual level of physical activity, but we also observed an independent correlation with serum concentrations of high-sensitivity C-reactive protein (hs-CRP), thus suggesting that inflammation may influence irisin production. In order to investigate the association between irisin and inflammation, we measured serum irisin concentrations in a group of inflamed inpatients. We hypothesized that if an association between irisin and inflammation exists, severely inflamed patients, even though physically inactive, might also exhibit high serum irisin levels. We recruited 40 consecutive markedly inflamed inpatients on the basis of serum CRP levels. Their irisin serum concentrations (Phoenix Europe, Germany) were compared with those obtained in the population-based cohort of the ABCD_2 study (Alimentazione, Benessere Cardiovascolare e Diabete) (ISRCTN15840340). The inflamed patients exhibited higher serum irisin concentrations (median: 6.77 ng/ml; 95% CI for the median: 5.97-7.23) than those observed in the ABCD cohort (median: 5.21 ng/ml; 95% CI for the median: 5.08-5.30; p <0.001). Irisin concentrations were significantly correlated with age (r=-0.44; p <0.001), creatinine (r=-0.35; p <0.05), and fibrinogen (r=0.40; p <0.05) concentrations. No association was observed between irisin, interleukine-6 and tumor necrosis factor alpha. This study confirms the association between inflammation and irisin concentrations. Further studies are needed to understand the mechanisms underlying this association and its possible clinical implications.

Does iris(in) bring bad news or good news?

Irisin, a novel myokine produced in response to physical activity, promotes white-to-brown fat transdifferentiation. The name irisin referred to the ancient Greek goddess Iris, the messenger who delivered (bad) news from the gods. In mice, it has been demonstrated that irisin plays a key role in metabolic regulation, energy expenditure and glucose homeostasis. New findings from various studies carried out in both animals and humans suggest that irisin might also have other favorable effects, such as increasing bone cortical mass, preventing hepatic lipid accumulation, and improving cognitive functions, thus mediating many exercise-induced health benefits. However, data on the role and function of irisin in humans have prompted controversy, due mostly to the only recent confirmation of the presence of irisin in humans. Another strong limitation to the understanding of irisin mechanisms of action is the lack of knowledge about its receptor, which until now remains unidentified in humans and in animals. This review presents an overall analysis of the history of irisin, its expression, and its involvement in health, especially in humans. Level of Evidence Level V, review.

High adherence to Mediterranean diet, but not individual foods or nutrients, is associated with lower likelihood of being obese in a Mediterranean cohort.

PURPOSE: The aim of the present study was to evaluate the association between the Mediterranean diet and obesity in a Mediterranean cohort. METHODS: The study population of MEAL (Mediterranean Healthy Eating, Ageing, and Lifestyle) study comprised 1814 men and women (18 + years) recruited in the city of Catania, southern Italy. Food intake was evaluated through a validated food frequency questionnaire and the Mediterranean diet adherence was assessed through the MEDI-LITE score. RESULTS: Individuals highly adherent to the Mediterranean diet (highest quartile of the score) were less likely to be obese (OR 0.53, 95% CI 0.32, 0.89) despite there was no significant associations when considering men and women separately. The dietary profile of obese and non-obese individuals did not significantly differ, except for vitamin E, processed meat, and alcohol more consumed among non-obese ones. Among the food groups characterizing this dietary pattern, only satisfaction of the criterion for dairy products (< 1 serving/day) was significantly associated with lower odds of being obese. Among other covariates, current smoking was associated with obesity, while high physical activity and regular alcohol drinking were inversely associated. Some differences between men and women in the highest category of occupational status occurred, as the former were less likely, while the latter were more likely to be obese. CONCLUSIONS: Higher adherence to the Mediterranean diet as a whole dietary pattern, rather than its individual components, is associated with less likelihood of being obese. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Ketogenic Diet, Physical Activity, and Hypertension-A Narrative Review.

Several studies link cardiovascular diseases (CVD) with unhealthy lifestyles (unhealthy dietary habits, alcohol consumption, smoking, and low levels of physical activity). Therefore, the strong need for CVD prevention may be pursued through an improved control of CVD risk factors (impaired lipid and glycemic profiles, high blood pressure, and obesity), which is achievable through an overall intervention aimed to favor a healthy lifestyle. Focusing on diet, different recommendations emphasize the need to increase or avoid consumption of entire classes of food, with only partly known and only partly foreseeable consequences on the overall level of health. In recent years, the ketogenic diet (KD) has been proposed to be an effective lifestyle intervention for metabolic syndrome, and although the beneficial effects on weight loss and glucose metabolism seems to be well established, the effects of a prolonged KD on the ability to perform different types of exercise and the influence of KD on blood pressure (BP) levels, both in normotensives and in hypertensives, are not so well understood. The objective of this review is to analyze, on the basis of current evidence, the relationship between KD, regular physical activity, and BP.

Obesity and Circulating Levels of Vitamin D before and after Weight Loss Induced by a Very Low-Calorie Ketogenic Diet.

Background: Vitamin D plays a pivotal role in calcium and phosphorus metabolism, also influencing bone tissue. Several studies have reported that vitamin D blood levels were significantly lower in people with obesity, probably due to its uptake by the adipose tissue. Clinical studies that investigated the changes of circulating levels of vitamin D following weight loss reported controversial data. A very low-calorie ketogenic diet is acknowledged as a reliable treatment to achieve a rapid weight loss. Therefore, we investigated the effect of weight loss, consequent to a very low-calorie ketogenic diet, on vitamin D blood concentrations. Methods: A cohort of 31 people with obesity underwent a very low-calorie ketogenic diet for 10-12 weeks. The serum concentrations of vitamin D, parathormone, calcium and phosphorous were measured before and after weight loss; they were compared to a control group of 20 non-obese, non-diabetic, age- and gender-matched persons. Results: Patients with obesity had a higher habitual intake of vitamin D than the control group (p < 0.05). However, the vitamin D blood levels of the obese group were significantly lower than those of the control group (p < 0.005) and they increased after weight loss (p < 0.001). At baseline, vitamin D blood concentrations of the persons with obesity were significantly correlated with both fat mass-kg (r = -0.40; p < 0.05) and body mass index (r = -0.47; p < 0.01). Following very low-calorie ketogenic diet, the change in vitamin D serum concentrations was correlated only with the change in fat mass-kg (r = -0.43; p < 0.01). Conclusion: This study confirmed that patients with obesity have lower vitamin D levels that normalize after significant weight loss, supporting the hypothesis that vitamin D is stored in the adipose tissue and released following weight loss.

Influence of Habitual Dairy Food Intake on LDL Cholesterol in a Population-Based Cohort.

BACKGROUND: Cholesterol has a pivotal role in human physiology, exerting both structural and functional activity. However, higher blood cholesterol levels, especially low-density lipoprotein cholesterol (LDL-C), are a major cardiovascular risk factor. Therefore, special attention has been given to the effect of dietary factors in influencing LDL-C blood levels. In particular, much research has focused on dairy products, since they are a main component of different dietary patterns worldwide. A large body of evidence did not support the hypothesis that dairy products significantly increase circulating LDL-C, but no definitive data are available. Hence, we aimed to assess the relationships among LDL-C, habitual dairy food intake and anthropometric variables in a cohort representative of the general population in a Mediterranean area. METHODS: We evaluated 802 healthy adults included in the ABCD_2 (Alimentazione, Benessere Cardiovascolare e Diabete) study (ISRCTN15840340), a longitudinal observational single-center study of a cohort representative of the general population of Palermo, Sicily. The habitual intake of dairy products was assessed with a validated food frequency questionnaire, and LDL-C serum levels and several anthropometric parameters were measured. RESULTS: The group with high LDL-C serum concentrations (≥130 vs. <130 mg/dL) exhibited higher age, body mass index (BMI), waist-to-hip ratio (WHR), body fat percentage, systolic and diastolic blood pressure, carotid intima-media thickness and glycated hemoglobin. The habitual diet was not different between the groups in terms of macronutrient, cholesterol, egg and dairy food intake, with the exception of the weekly number of portions of milk (higher in the low LDL-C group vs. the high LDL-C group) and ricotta cheese (higher in the high LDL-C group vs. the LDL-C group). No significant correlation was found between LDL-C blood levels and the habitual intake of dairy products or the dietary intake of cholesterol and fats. The multivariate regression analyses (R2 = 0.94) showed that LDL-C blood levels were significantly associated with the habitual intake of milk (p < 0.005) and ricotta cheese (p < 0.001) and with BMI (p < 0.001). CONCLUSION: Our study reported that total dairy food consumption was not correlated with LDL-C blood levels. However, multivariate analyses showed an inverse association between serum LDL-C and milk intake as well as a positive association between ricotta cheese intake and LDL-C concentrations. More studies are needed to better characterize the relationship between dairy products and circulating LDL-C.

Endothelial Function in Obese Patients Treated with Bariatric Surgery.

PURPOSE: Bariatric surgery (BS) is becoming an increasingly frequent treatment option especially in people with morbid obesity, demonstrating that it is able to reduce total mortality and cardiovascular (CV) risk. Despite endothelial dysfunction is an essential requisite contributing to atherosclerosis and predicting CV events, only some studies have investigated the effects of BS on endothelial function with controversial results. In this study, the effects of weight loss on endothelial function were investigated in obese patients after BS and compared with patients after medical nutrition treatment (MNT). PATIENTS AND METHODS: Seventeen obese patients who underwent BS procedures (9 adjustable gastric bands, 3 gastric by-passes and 5 biliopancreatic diversions) were included in the study and compared with 18 obese individuals who underwent MNT. Endothelial function was investigated by flow-mediated dilation (FMD) of the brachial artery. Also, carotid intima-media thickness (c-IMT) was measured as a marker of subclinical atherosclerosis. RESULTS: At the end of follow-up, the mean weight loss was 18.8% in the BS group and 7.0% in the MNT group. After treatment, FMD significantly decreased in the BS group (mean ± SD before: 9.0 ± 4.7; after: 6.1 ± 2.9%; P= 0.04); however, no significant change was observed in the MNT group (before: 9.4 ± 5.8; after: 8.3 ± 5.3; P= 0.41). The modification of endothelial function was negatively correlated with c-IMT change in the BS group (r= -0.63; P <0.007). CONCLUSION: A significant endothelial dysfunction occurred following BS but not after MNT. Furthermore, the decline of endothelial function observed in the BS group might have contributed to atherosclerosis.

The Effect of Lutein on Eye and Extra-Eye Health.

Lutein is a carotenoid with reported anti-inflammatory properties. A large body of evidence shows that lutein has several beneficial effects, especially on eye health. In particular, lutein is known to improve or even prevent age-related macular disease which is the leading cause of blindness and vision impairment. Furthermore, many studies have reported that lutein may also have positive effects in different clinical conditions, thus ameliorating cognitive function, decreasing the risk of cancer, and improving measures of cardiovascular health. At present, the available data have been obtained from both observational studies investigating lutein intake with food, and a few intervention trials assessing the efficacy of lutein supplementation. In general, sustained lutein consumption, either through diet or supplementation, may contribute to reducing the burden of several chronic diseases. However, there are also conflicting data concerning lutein efficacy in inducing favorable effects on human health and there are no univocal data concerning the most appropriate dosage for daily lutein supplementation. Therefore, based on the most recent findings, this review will focus on lutein properties, dietary sources, usual intake, efficacy in human health, and toxicity.

Association of obesity and diabetes with thyroid nodules.

AIM: There are conflicting data concerning the possibility that obesity and diabetes raise the risk of thyroid nodules. The incidence of thyroid nodules is increasing, as is that of obesity and diabetes; therefore, understanding whether these metabolic and nutritional disorders influence nodular thyroid disease is important for organizing prevention strategies. This study investigated the association between thyroid nodules, obesity, diabetes, and dietary habits. MATERIALS AND METHODS: A cohort of randomly selected adults (455 males, 746 females; age: 18-90 years) living in Palermo (Italy), a mild iodine deficiency area, was cross-sectionally investigated. Participants underwent high-resolution ultrasonographic evaluation of the thyroid, and answered a food frequency questionnaire. Laboratory blood measurements were obtained in 587 participants. RESULTS AND DISCUSSION: Thyroid nodules were detected in 475 (39.5%) participants. The number of thyroid nodules was correlated with age (r = 0.19; P < 0.001), gender (r = 0.08; P = 0.005), and body mass index (r = 0.07; P = 0.02). No significant correlation was observed between the number of nodules and glycated hemoglobin, serum insulin concentrations, and homeostasis model assessment of insulin resistance. Age-adjusted and gender-adjusted prevalence of both overweight/obesity and type 2 diabetes of each group of participants divided according to the number of nodules significantly increased with the number of nodules (P < 0.05 in both cases). The group of participants with nodules exhibited a significantly lower age-adjusted and gender-adjusted habitual intake of milk (P = 0.02). Multivariate regression analysis showed that age, gender, body mass index, diabetes, and habitual consumption of milk were independently correlated with presence of thyroid nodules. CONCLUSION: This study seems to indicate that an association exists between obesity, diabetes, and thyroid nodules.

Characterization of Metabolically Healthy Obese People and Metabolically Unhealthy Normal-Weight People in a General Population Cohort of the ABCD Study.

There is actually no consensus about the possibility that in some instances, obesity may be a benign metabolically healthy (MH) condition as opposed to a normal-weight but metabolically unhealthy (MUH) state. The aim of this study was to characterize MH condition and to investigate possible associations with metabolic and cardiovascular complications. One thousand nineteen people (range of age 18-90 years) of the cohort of the ABCD_2 study were investigated. Participants were classified as normal weight (BMI < 24.9 kg/m2) or overweight-obese (BMI ≥25 kg/m2); they were also classified as MH in the presence of 0-1 among the following conditions: (a) prediabetes/type 2 diabetes, (b) hypertension, (c) hypertriglyceridemia or low HDL cholesterolemia, and (d) hypercholesterolemia. MUH condition was diagnosed if ≥2 of the conditions listed were found. The prevalence of overweight/obese people was 71.1%, of whom 27.4% were found to be MH. In addition, 36.7% of the normal-weight participants were MUH. HOMA-IR, high sensitivity C-reactive protein, and the carotid intima-media thickness were significantly different in the 4 subgroups (P < 0.001), with higher values observed in the MUH normal-weight and obese groups. In conclusion, this study highlights the importance of identifying a MH condition in normal-weight and in obese people in order to offer better treatment.