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Dive into the research topics where Christos M. Hatzis is active.

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Featured researches published by Christos M. Hatzis.


British Journal of Nutrition | 2002

Health and nutrition education in primary schools of Crete: changes in chronic disease risk factors following a 6-year intervention programme.

Yannis Manios; Joanna Moschandreas; Christos M. Hatzis; Anthony Kafatos

The effectiveness of a health and nutrition education programme, in changing certain chronic disease risk factors, was assessed after the 6 years intervention period was completed. The school-based intervention programme was applied to all children registered in the first grade (age 5.5-6.5 years) in 1992 in two counties of Crete, while the children from a third county served as a control group. In order to assess the effectiveness of the intervention, a variety of biological and behavioural parameters were measured before and following completion of the intervention in a randomly selected school-based sample of 602 intervention group (IG) and 444 control group (CG) pupils. At the end of the 6-year period, it was found that biochemical indices generally improved significantly more in the IG compared with the CG (mean change for IG v. CG was -0.27 v. -0.12 mmol/l for total cholesterol (TC); -0.07 v. +0.24 for TC:HDL and -0.13 v. +0.14 for LDL:HDL). Similarly, the changes observed in the anthropometric variables in the two groups were in favour of the IG (+3.68 v. +4.28 kg/m2 for BMI; +2.97 v. +4.47 mm for biceps skinfold). Total energy intake and consumption of total fat and saturated fat increased significantly less in the IG compared with the CG (+747.7 v. 1534.7 kJ (+178.7 v. +366.8 kcal); +5.9 v. +18.8 g and +0.8 v. +5.1 g respectively), while time devoted to leisure time physical activity and cardiovascular run test performance increased significantly more in the IG (+281 v. +174 min/week and +2.5 v. +1.2 stages respectively). The findings of the present study underline the importance of such programmes in health promotion and disease prevention. Although the long-term effects of these programmes can only be assessed by tracking this population through to adolescence and adulthood, these programmes seem to have the potential to lead to a healthier lifestyle and thus a reduction in risk factor levels.


British Journal of Nutrition | 2004

Association of adipose tissue arachidonic acid content with BMI and overweight status in children from Cyprus and Crete

Savvas C. Savva; Charalambos Chadjigeorgiou; Christos M. Hatzis; Michael Kyriakakis; George Tsimbinos; Michael Tornaritis; Anthony Kafatos

The relationships between n-3 and n-6 fatty acids in subcutaneous fat, BMI and overweight status were investigated in eighty-eight children from Crete and Cyprus. Overweight status, BMI and serum lipid levels were similar in children at both locations, but Cretan children had higher levels of total MUFA than Cypriot children (62.2 (sd 2.8) v. 52.2 (sd 2.8) % area, respectively, P<0.001) and consequently Cypriot children had higher levels of total saturated, polyunsaturated, trans, n-3 and n-6 fatty acids. Cypriot children had also higher levels of individual n-3 and n-6 fatty acids, specifically linoleic, alpha-linolenic and dihomo-gamma-linolenic acids. The variance of BMI was better explained (38.2 %) by adipose tissue arachidonic acid content than any other n-3 and n-6 fatty acids. Mean levels of arachidonic acid, dihomo-gamma-linolenic acid and docosahexaenoic acid were higher in overweight and obese subjects. All obese subjects fell in the 4th quartile of arachidonic acid levels, whereas 88.9 % of overweight subjects fell in the 3rd and 4th quartile of arachidonic acid. These results indicate positive associations between adipose tissue arachidonic acid and BMI and overweight status. Further research could clarify whether this association is causal.


European Journal of Clinical Nutrition | 2006

Depression and long chain n-3 fatty acids in adipose tissue in adults from Crete

George Mamalakis; Nick Kalogeropoulos; Nikolaos K. Andrikopoulos; Christos M. Hatzis; Daan Kromhout; Joanna Moschandreas; A Kafatos

Background:Only one study has investigated the relationship of essential fatty acids in the adipose tissue with depression in adults and suggested an inverse relationship between docosahexaenoic acid (22:6 n-3) (DHA) and depression.Objective:To examine the relation between adipose tissue polyunsaturated fatty acids especially n-3 and n-6 fatty acids, an index of long-term or habitual fatty acid intake, and depression in adults.Design:Cross-sectional study of healthy adults from the island of Crete.Setting:The Preventive Medicine and Nutrition Clinic, University of Crete, Greece.Subjects:A total of 130 healthy adults (59 males, 71 females) aged 22—58 years. The sample was a sub-sample of the Greek ApoEurope study group.Methods:Fatty acids were determined by gas chromatography in adipose tissue. Information about depression was obtained through the Zung Self-rating Depression Scale.Results:Adipose tissue DHA was inversely related with depression. Multiple linear regression analysis taking into account the possible confounding effect of age, gender, body mass index, smoking and educational level confirmed this association.Conclusions:The inverse relationship between adipose DHA and depression in adults, replicates findings of a previous study. This relationship indicates that a low long-term dietary intake of DHA is associated with an increased risk for depression in adults.Funding:The International Olive Oil Council and the DG XII of the European Union.


Pharmacology, Biochemistry and Behavior | 2006

Depression and serum adiponectin and adipose omega-3 and omega-6 fatty acids in adolescents

George Mamalakis; Michael Kiriakakis; George Tsibinos; Christos M. Hatzis; Sofia Flouri; Christos S. Mantzoros; Anthony Kafatos

The purpose of the present study was to investigate for a possible relationship between depression and serum adiponectin and adipose tissue omega-3 and omega-6 PUFA. The sample consisted of 90 healthy adolescent volunteers from the island of Crete. There were 54 girls and 36 boys, aged 13 to 18. The mean age was 15.2 years. Subjects were examined by the Preventive Medicine and Nutrition Clinic of the University of Crete. Depression was assessed through the use of the Beck Depression Inventory (BDI) and the Center for Epidemiologic Studies Depression Scale (CES-D). Fatty acids were determined by gas chromatography in adipose tissue. CES-D correlated with dihomo-gamma linolenic acid (DGLA). Multiple linear regression analyses showed that BDI was negatively associated with eicosapentaenoic acid (EPA), while CES-D was positively associated with DGLA in adipose tissue. Serum adiponectin was not significantly associated with depression. The negative relationship between adipose EPA and depression in adolescents, is in line with findings of previous studies involving adult and elderly subjects, demonstrating negative relations between depression and adipose omega-3 PUFA. This is the first literature report of a relationship between depression and an individual omega-3 fatty acid in adolescents. The inverse relationship between adipose EPA and depression indicates that a low long-term dietary intake of EPA is associated with an increased risk for depression in adolescents.


Nutrition Journal | 2006

Dietary and other lifestyle correlates of serum folate concentrations in a healthy adult population in Crete, Greece: a cross-sectional study

Christos M. Hatzis; George Bertsias; Manolis Linardakis; John M. Scott; Anthony Kafatos

BackgroundFolate has emerged as a key nutrient for optimising health. Impaired folate status has been identified as a risk factor for cardiovascular disease, various types of cancers, and neurocognitive disorders. The study aimed at examining the distribution and determinants of serum folate concentrations in a healthy adult population in Crete, Greece.MethodsA cross-sectional sample of 486 healthy adults (250 men, 236 women) aged 39 ± 14 years, personnel of the Medical School and the University Hospital of Crete in Greece, was examined. Serum folate and vitamin B12 concentrations were measured by microbiological assay, and total homocysteine was determined fluorometrically and by high-pressure liquid chromatography. Lifestyle questionnaires were completed, and nutrient intakes and food consumption were assessed by 24-h dietary recalls. Multivariate analyses were performed using SPSS v10.1.ResultsThe geometric mean (95% confidence interval) concentrations of serum folate were 15.6 μmol/l (14.6–16.8) in men and 19.2 μmol/l (17.9–20.7) in women (p < 0.001). Inadequate folate levels (≤7 nmol/l) were present in 6.8% of men and 2.1% of women (p < 0.001). Approximately 76% of men and 87% of women did not meet the reference dietary intake for folate (400 μg/day). Serum folate was inversely related to total homocysteine levels (p < 0.001). Increased tobacco and coffee consumption were associated with lower folate concentrations (p < 0.05 for both) but these associations disappeared after controlling for nutrient intakes. In multivariate analysis, intakes of MUFA, fibre, calcium, magnesium, folate, and vitamins A, E, C, B1, and B6 were positively associated with serum folate. Consumption of potatoes, legumes, fruits, and vegetables were favourably related to the serum folate status.ConclusionSerum folate concentrations were associated with various demographic, lifestyle and dietary factors in healthy Cretan adults. Large-scale epidemiological studies should be conducted within the general Greek adult population to assess the prevalence of impaired folate status and further examine associations with dietary patterns and chronic disease risk. Considering the importance of folate in health maintenance, it is important to increase the publics awareness of modifiable lifestyle patterns and diet and tobacco use in particular, which may be associated with improved folate status.


Tobacco Induced Diseases | 2008

Smoking status in relation to serum folate and dietary vitamin intake

Constantine I. Vardavas; Manolis Linardakis; Christos M. Hatzis; Niki Malliaraki; Wim H. M. Saris; Anthony Kafatos

ObjectiveCigarette smoke itself is an abundant source of free radicals and a major cause of oxidative stress, to which plasma antioxidants function as a vital protective and counterbalancing mechanism. The objective of this study was to investigate into the relationship between smoking status and serum and dietary micronutrient concentrations.DesignCross-sectional studySubjects – Setting502 farmers from the Valley of Messara in Crete were randomly selected and examined. Complete three-day and 24-hr recall questionnaires were collected along with anthropometrical, physical activity and clinical data from all participating subjects.ResultsAfter adjusting for age, gender and number of fasting days adhered to per year, current smokers were found to have a lower dietary intake of vitamin C (112.1 mg vs. 136.4 mg, p = 0.03), fibre (16.6 g vs. 19.1 g, p = 0.006) and fruits and vegetables (339 g vs. 412 g, p = 0.014), while dietary vitamin B1 intake was found to be higher (1.7 mg vs. 1.4 mg, p = 0.02) in comparison to non/ex smokers. Dietary intake of meat, folate and vitami A, E, B2, B6 and B12 did not differ between the groups. Controlling age, gender, fasting days and dietary micronutrient intake, serum folate levels were found to be lower among smokers (geometric mean 15.3 nmol/L vs. 17.7 nmol/L, p = 0.023), while serum iron and vitamin B12 levels were not affected by smoking status.ConclusionCurrent smoking status affects dietary nutrient intake as well as plasma folate levels. The above coherence between antioxidant depletion and reduced antioxidant intake may predispose smokers to the premature development of tobacco related mortality and morbidity.


European Journal of Preventive Cardiology | 2010

Cardiovascular disease risk factors and dietary habits of farmers from Crete 45 years after the first description of the Mediterranean diet.

Constantine I. Vardavas; Manolis Linardakis; Christos M. Hatzis; Wim H. M. Saris; Anthony Kafatos

Background Farmers from Crete as first studied within the framework of the Seven Countries Study, were historically known for holding the title of the ‘gold standard’ of health status globally and had a very low prevalence of both cardiovascular disease (CVD) and cancer. Taking the above into account we evaluated the changes in CVD risk factors among farmers in Crete, Greece and compared our findings with data from the 1960s. Design Cross-sectional. Methods Five hundred and two farmers (18–79 years old) from the Valley of Messara in Crete were randomly selected and examined in 2005. Complete clinical, biochemical, dietetic, anthropometrical and lifestyle CVD risk factors were assessed, matched and compared with published data from the 1960s. Results In comparison with 45 years ago, present day male farmers from Crete were found to have a 30% higher BMI (29.8 vs. 22.9 kg/m2, P [0.001) and a 16% higher total cholesterol level (239.6 vs. 206.9 mg/dl, P[ 0.001) and also a not so favourable daily dietary intake (increase in meat and saturated fat and decrease in fruit, P [0.001, respectively), while a significant reduction in systolic blood pressure and energy intake was noticed. In regards to changes in subcutaneous adipose tissue fatty acid composition, a decrease in monounsaturated (P [ 0.001) and an increase in saturated fatty acids (P[ 0.001) was also found elucidating the temporal change in dietary habits. Conclusion The populations lack of adherence to the Mediterranean diet, have led to the fact that currently farmers from Crete are likely to be at a higher risk for developing CVD in comparison with earlier generations.


European Respiratory Journal | 2012

Effect of Mediterranean diet versus prudent diet combined with physical activity on OSAS: a randomised trial

Christopher Papandreou; Sophia E. Schiza; Izolde Bouloukaki; Christos M. Hatzis; Anthony Kafatos; Nikolaos M. Siafakas; Nikolaos Tzanakis

We aimed to evaluate the effect of the Mediterranean diet (MD) compared with a prudent diet (PD) combined with physical activity on obese obstructive sleep apnoea syndrome (OSAS) patients who were treated with continuous positive airway pressure. 900 patients were evaluated and 40 obese patients (body mass index ≥30.0 kg·m−2) who met the inclusion criteria, with moderate-to-severe OSAS (apnoea–hypopnoea index (AHI) >15 events·h−1 and Epworth Sleepiness Scale score >10) based on overnight attended polysomnography, were included in the study. After randomisation, 20 patients followed the MD and 20 a PD for a 6-month period. All patients were counselled to increase their physical activity. Concerning sleep parameters, only AHI during rapid eye movement (REM) sleep was reduced to a statistically significant degree, by mean±sd 18.4±17.6 events·h−1 in the MD group and by 2.6±23.7 events·h−1 in the PD group (p<0.05). The MD group also showed a greater reduction in waist circumference (WC) (-8.7±3.6 cm), WC/height ratio (-0.04±0.02 cm·m−1) and WC/hip ratio (-0.04±0.03 cm·cm−1), compared with the other group (-2.6±1.7 events·h−1, -5.7±3.8 cm, -0.03±0.02 cm·m−1 and 0.02±0.02 cm·cm−1, respectively; p<0.05). Our results showed that the MD combined with physical activity for a 6-month period was effective in reducing the AHI during REM sleep without any statistically significant effect in the other sleep parameters, compared with a PD in obese adults with moderate-to-severe OSAS.


Nutrition Metabolism and Cardiovascular Diseases | 2009

Prevalence of obesity and physical inactivity among farmers from Crete (Greece), four decades after the Seven Countries Study.

Constantine I. Vardavas; Manolis Linardakis; Christos M. Hatzis; Wim H. M. Saris; Anthony Kafatos

BACKGROUND AND AIM As first shown 40 years ago farmers from Crete had one of the healthiest lifestyles compared to other participants of the Seven Countries Study. Taking the above into account we investigated the prevalence of obesity and its indexes among farmers in Crete in 2005. METHODS AND RESULTS 502 farmers (18-79 years old) from the Valley of Messara in Crete were randomly selected and examined. Body Mass Index (BMI), waist circumference (WC), waist-to-hip ratio (W/Hip Ratio), waist-to-height ratio (W/Height Ratio), conicity index, percentage of body fat and hours of daily light physical activity (LPhA) and moderate-to-vigorous physical activity (MVPhA) were calculated for each subject. 86,1% of the study population was overweight and/or obese. Specifically 42.9% had a BMI of 25.1-30 kg/m(2) and were overweight and 43.2% were obese with a BMI>30 kg/m(2). The percentage of body fat was estimated at 27.3% of total body weight among males and 39.3% among females, while all obesity indexes were found to differ between genders. CONCLUSIONS In comparison to middle aged male farmers from Crete in the 1960s, mean weight has increased by 20 kg (83 kg vs. 63 kg), which has lead to a 7 kg/m(2) in mean BMI (22.9 kg/m(2) vs. 29.8 kg/m(2)), findings that support the fact that the prevalence of obesity in Greece has risen dramatically over the years, even among farmers from Crete, a population historically known for being the gold standard of health status globally.


Pharmacology, Biochemistry and Behavior | 2008

Lack of an association of depression with n-3 polyunsaturated fatty acids in adipose tissue and serum phospholipids in healthy adults

George Mamalakis; Michael Kiriakakis; George Tsibinos; Eugene Jansen; Hans Cremers; Carlo Strien; Christos M. Hatzis; Joanna Moschandreas; Manolis Linardakis; Daan Kromhout; Anthony Kafatos

Studies have shown that depression relates to biomarkers of both short-term and long-term polyunsaturated fatty acid intake. However, it is not known which of these two biomarkers is more closely related to depression. The aim of this study was to examine the relationship of depression with both adipose tissue and serum phospholipid polyunsaturated fatty acids and to assess the importance of each of these two biomarkers in relating to depression. This is a cross-sectional study of healthy adults from the island of Crete. Subjects were examined by the Preventive Medicine and Nutrition Clinic of the University of Crete. Subjects were 394 healthy adults (175 males, 219 females) aged 18-60. The sample consisted of farmers from a number of rural communities of Crete. Fatty acids were determined by gas chromatography in adipose tissue and serum phospholipids. Information about depression was obtained through the Beck Depression Inventory (BDI) and Zung Self-rating Depression Scale (ZSRDS). Adipose tissue alpha-linolenic acid (ALA) (C18:3n-3) was inversely correlated to BDI (r=-0.17, p<0.02). Multiple linear regression analysis taking into account the possible confounding effect of age, gender, body mass index (BMI), smoking and educational level did not confirm this association. The other polyunsaturated fatty acids in adipose tissue were not related to depression. Serum phospholipid polyunsaturated fatty acids did not correlate with depression. This study did not show that the polyunsaturated fatty acids in the adipose tissue are better predictors of depression than those in serum phospholipids.

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