Carmen Di Palo

CONTEXT: The metabolic syndrome has been identified as a target for dietary therapies to reduce risk of cardiovascular disease; however, the role of diet in the etiology of the metabolic syndrome is poorly understood. OBJECTIVE: To assess the effect of a Mediterranean-style diet on endothelial function and vascular inflammatory markers in patients with the metabolic syndrome. DESIGN, SETTING, AND PATIENTS: Randomized, single-blind trial conducted from June 2001 to January 2004 at a university hospital in Italy among 180 patients (99 men and 81 women) with the metabolic syndrome, as defined by the Adult Treatment Panel III. INTERVENTIONS: Patients in the intervention group (n = 90) were instructed to follow a Mediterranean-style diet and received detailed advice about how to increase daily consumption of whole grains, fruits, vegetables, nuts, and olive oil; patients in the control group (n = 90) followed a prudent diet (carbohydrates, 50%-60%; proteins, 15%-20%; total fat, <30%). MAIN OUTCOME MEASURES: Nutrient intake; endothelial function score as a measure of blood pressure and platelet aggregation response to l-arginine; lipid and glucose parameters; insulin sensitivity; and circulating levels of high-sensitivity C-reactive protein (hs-CRP) and interleukins 6 (IL-6), 7 (IL-7), and 18 (IL-18). RESULTS: After 2 years, patients following the Mediterranean-style diet consumed more foods rich in monounsaturated fat, polyunsaturated fat, and fiber and had a lower ratio of omega-6 to omega-3 fatty acids. Total fruit, vegetable, and nuts intake (274 g/d), whole grain intake (103 g/d), and olive oil consumption (8 g/d) were also significantly higher in the intervention group (P<.001). The level of physical activity increased in both groups by approximately 60%, without difference between groups (P =.22). Mean (SD) body weight decreased more in patients in the intervention group (-4.0 [1.1] kg) than in those in the control group (-1.2 [0.6] kg) (P<.001). Compared with patients consuming the control diet, patients consuming the intervention diet had significantly reduced serum concentrations of hs-CRP (P =.01), IL-6 (P =.04), IL-7 (P = 0.4), and IL-18 (P = 0.3), as well as decreased insulin resistance (P<.001). Endothelial function score improved in the intervention group (mean [SD] change, +1.9 [0.6]; P<.001) but remained stable in the control group (+0.2 [0.2]; P =.33). At 2 years of follow-up, 40 patients in the intervention group still had features of the metabolic syndrome, compared with 78 patients in the control group (P<.001). CONCLUSION: A Mediterranean-style diet might be effective in reducing the prevalence of the metabolic syndrome and its associated cardiovascular risk.

CONTEXT: Obesity is an independent risk factor for cardiovascular disease, which may be mediated by increased secretion of proinflammatory cytokines by adipose tissue. OBJECTIVE: To determine the effect of a program of changes in lifestyle designed to obtain a sustained reduction of body weight on markers of systemic vascular inflammation and insulin resistance. DESIGN AND SETTING: Randomized single-blind trial conducted from February 1999 to February 2002 at a university hospital in Italy. PATIENTS: One hundred twenty premenopausal obese women (body mass index > or =30) aged 20 to 46 years without diabetes, hypertension, or hyperlipidemia. INTERVENTIONS: The 60 women randomly assigned to the intervention group received detailed advice about how to achieve a reduction of weight of 10% or more through a low-energy Mediterranean-style diet and increased physical activity. The control group (n = 60) was given general information about healthy food choices and exercise. MAIN OUTCOME MEASURES: Lipid and glucose intake; blood pressure; homeostatic model assessment of insulin sensitivity; and circulating levels of interleukin 6 (IL-6), interleukin 18 (IL-18), C-reactive protein (CRP), and adiponectin. RESULTS: After 2 years, women in the intervention group consumed more foods rich in complex carbohydrates (9% corrected difference; P<.001), monounsaturated fat (2%; P =.009), and fiber (7 g/d; P<.001); had a lower ratio of omega-6 to omega-3 fatty acids (-5; P<.001); and had lower energy (-310 kcal/d; P<.001), saturated fat (-3.5%; P =.007), and cholesterol intake (-92 mg/d; P<.001) than controls. Body mass index decreased more in the intervention group than in controls (-4.2; P<.001), as did serum concentrations of IL-6 (-1.1 pg/mL; P =.009), IL-18 (-57 pg/mL; P =.02), and CRP (-1.6 mg/L; P =.008), while adiponectin levels increased significantly (2.2 microg/mL; P =.01). In multivariate analyses, changes in free fatty acids (P =.008), IL-6 (P =.02), and adiponectin (P =.007) levels were independently associated with changes in insulin sensitivity. CONCLUSION: In this study, a multidisciplinary program aimed to reduce body weight in obese women through lifestyle changes was associated with a reduction in markers of vascular inflammation and insulin resistance.

CONTEXT: Healthy lifestyle factors are associated with maintenance of erectile function in men. OBJECTIVE: To determine the effect of weight loss and increased physical activity on erectile and endothelial functions in obese men. DESIGN, SETTING, AND PATIENTS: Randomized, single-blind trial of 110 obese men (body mass index > or =30) aged 35 to 55 years, without diabetes, hypertension, or hyperlipidemia, who had erectile dysfunction that was determined by having a score of 21 or less on the International Index of Erectile Function (IIEF). The study was conducted from October 2000 to October 2003 at a university hospital in Italy. INTERVENTIONS: The 55 men randomly assigned to the intervention group received detailed advice about how to achieve a loss of 10% or more in their total body weight by reducing caloric intake and increasing their level of physical activity. Men in the control group (n = 55) were given general information about healthy food choices and exercise. MAIN OUTCOMES MEASURES: Erectile function score, levels of cholesterol and triglycerides, circulating levels of interleukin 6, interleukin 8, and C-reactive protein, and endothelial function as assessed by vascular responses to l-arginine. RESULTS: After 2 years, body mass index decreased more in the intervention group (from a mean [SD] of 36.9 [2.5] to 31.2 [2.1]) than in the control group (from 36.4 [2.3] to 35.7 [2.5]) (P<.001), as did serum concentrations of interleukin 6 (P =.03), and C-reactive protein (P =.02). The mean (SD) level of physical activity increased more in the intervention group (from 48 [10] to 195 [36] min/wk; P<.001) than in the control group (from 51 [9] to 84 [28] min/wk; P<.001). The mean (SD) IIEF score improved in the intervention group (from 13.9 [4.0] to 17 [5]; P<.001), but remained stable in the control group (from 13.5 [4.0] to 13.6 [4.1]; P =.89). Seventeen men in the intervention group and 3 in the control group (P =.001) reported an IIEF score of 22 or higher. In multivariate analyses, changes in body mass index (P =.02), physical activity (P =.02), and C-reactive protein (P =.03) were independently associated with changes in IIEF score. CONCLUSION: Lifestyle changes are associated with improvement in sexual function in about one third of obese men with erectile dysfunction at baseline.

BACKGROUND: Low-carbohydrate and low-fat calorie-restricted diets are recommended for weight loss in overweight and obese people with type 2 diabetes. OBJECTIVE: To compare the effects of a low-carbohydrate Mediterranean-style or a low-fat diet on the need for antihyperglycemic drug therapy in patients with newly diagnosed type 2 diabetes. DESIGN: Single-center, randomized trial. Randomization was computer-generated and unstratified. Allocation was concealed in sealed study folders held in a central, secure location until participants gave informed consent. Participants and investigators were aware of treatment assignment, and assessors of the primary outcome were blinded. SETTING: Teaching hospital in Naples, Italy. PATIENTS: 215 overweight people with newly diagnosed type 2 diabetes who were never treated with antihyperglycemic drugs and had hemoglobin A(1c) (HbA(1c)) levels less than 11%. INTERVENTION: Mediterranean-style diet (<50% of daily calories from carbohydrates) (n = 108) or a low-fat diet (<30% of daily calories from fat) (n = 107). MEASUREMENTS: Start of antihyperglycemic drug therapy, defined by protocol as indicated for follow-up HbA(1c) level greater than 7% (primary outcome), and changes in weight, glycemic control, and coronary risk factors (secondary outcomes). RESULTS: After 4 years, 44% of patients in the Mediterranean-style diet group and 70% in the low-fat diet group required treatment (absolute difference, -26.0 percentage points [95% CI, -31.1 to -20.1 percentage points]; hazard ratio, 0.63 [CI, 0.51 to 0.86]; hazard ratio adjusted for weight change, 0.70 [CI, 0.59 to 0.90]; P < 0.001). Participants assigned to the Mediterranean-style diet lost more weight and experienced greater improvements in some glycemic control and coronary risk measures than did those assigned to the low-fat diet. LIMITATIONS: Investigators responsible for initiating drug therapy were not blinded to treatment assignment. Dietary intake was self-reported. CONCLUSION: Compared with a low-fat diet, a low-carbohydrate, Mediterranean-style diet led to more favorable changes in glycemic control and coronary risk factors and delayed the need for antihyperglycemic drug therapy in overweight patients with newly diagnosed type 2 diabetes. PRIMARY FUNDING SOURCE: Second University of Naples.

Obesity is associated with an increased risk of developing atherosclerosis, which may be mediated, at least in part, by increased secretion of proinflammatory cytokines by adipose tissue. We examined the hypothesis that circulating levels of IL-18 were elevated in obese women and would be reduced by weight loss. In a sample of 40 obese (body mass index, 36.4 +/- 3.1 kg/m(2)) women we found that plasma IL-18 levels were higher than in 40 normal weight control women (P < 0.01) and were positively associated with body weight (r = 0.46; P < 0.01) and visceral fat (waist to hip ratio; r = 0.39; P < 0.01). Caloric restriction-induced weight loss (> or = 10% of original weight) over 1 yr reduced IL-18 levels from 247 (204/309) to 147 (111/210) pg/ml (medians and 25%/75%; P < 0.01), positively associated with changes in body mass index and waist to hip ratio. In obese women, IL-18 levels are associated with body weight and abdominal fat deposition; weight loss is an important intervention to reduce IL-18 levels. IL-18 may be a novel cytokine operating in human obesity.