Vol 25 No 3 June 2014
URRENT C OPINION Current Opinion in Lipidology
Bimonthly update This section provides a rapid update service, covering the whole field of lipidology, and lists papers entered into the publisher’s database from OvidSP.
Contents
Key articles are selected for comment by specialists and are highlighted in the following way:
228 Dietary fish intake and the risk for type 2 diabetes and cardiovascular disease: new insights Janine Kro¨ger and Matthias B. Schulze
Papers considered to be of specialist interest Papers considered to be of outstanding interest A bibliographic listing follows each comment and selected papers are accompanied by an annotation in which the scope and context of the article are summarized briefly.
Edited by Alan Rees
230 High-density lipoproteins: taking the good with the bad Charles E. Sparks, James P. Corsetti and Janet D. Sparks 233 Bariatric surgery and cardiovascular risk reduction Laxmi Narsimha Rao Bondugulapati, Vinay S. Eligar and Alan Rees
Current Opinion in Lipidology 2014, 25:228–238 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins 0957-9672
235 Atherosclerosis: cell biology and lipoproteins epigenetics and oxidation in atherosclerosis Silvio Zaina and Gertrud Lund 237 Management of homozygous familial hypercholesterolaemia Vinay S. Eligar, Laxmi N.R. Bondugulapati and Alan Rees
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
EDITORIAL COMMENT URRENT C OPINION
Dietary fish intake and the risk for type 2 diabetes and cardiovascular disease: new insights Janine Kro¨ger and Matthias B. Schulze
Current dietary guidelines emphasize regular consumption of fish, with at least two servings of fish per week, one of which should be sea fish. Longchain n-3 polyunsaturated fatty acids (PUFAs), mainly found in fatty fish, have been attributed beneficial effects on cardiovascular risk factors like vascular resistance, inflammation and blood lipids [1]. Trials with fish oil supplements resulted in lower coronary heart disease (CHD) mortality [2], whereas no clear benefit was observed on glucose-insulin homeostasis [3]; however, results were mixed. As no long-term trials have been conducted yet, large observational studies with long follow-up could provide valuable insight. In prospective observational studies, fish intake was associated with lower CHD risk and CHD mortality [4,5]. As for type 2 diabetes, there was no clear association of intakes of fish or eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) with risk in recent meta-analyses [6–11]. However, results of the original studies were mixed and there was significant heterogeneity based on the geographical region of the study population (inverse association in Asian/Australian populations, no association in European populations, direct association in US populations). The purpose of this article is to summarize the most important findings from observational studies published during the last year. Only recently, three new articles on blood proportions of long-chain n-3 PUFAs and diabetes risk have been published. In the Finnish METSIM study with 5-year follow-up, neither erythrocyte EPA and DHA [12 ] nor serum DHA [13], which are regarded as biomarkers of intake, showed a significant association with diabetes risk. Of note, there was also no significant association of these biomarkers with insulin sensitivity or secretion at 5-year follow-up, which is a novel finding. Virtanen et al. [14 ] analyzed data of another Finnish cohort with 19 years of follow-up and observed inverse associations for serum long-chain n-3 PUFAs; however, results were not significant for EPA. Reasons for these divergent findings are unknown. Duration of follow-up seems an unlikely explanation here because the detection of inverse associations has been associated with &
short follow-up periods in recent meta-analyses [7,8]. Fish and seafood products are the major dietary sources of mercury accumulation in the body, which was related to b-cell function in experimental models. During the last year, the first studies relating biomarkers of mercury exposure to diabetes incidence have emerged. In the CARDIA study, toenail mercury levels were positively associated with diabetes risk after adjustment for long-chain n-3 PUFAs [15 ]. However, this was not confirmed by analyses of the Health Professionals Follow-Up Study (HPFS) and the Nurses’ Health Study (NHS) [16]. Virtanen et al. [14 ] also did not observe a significant relation for hair mercury; however, no adjustment for longchain n-3 PUFAs was made. Given these inconsistent findings, further studies should explore the role of mercury exposure for diabetes risk. As for CHD, an interesting analysis of the HPFS and the NHS has been published recently addressing the relevant question whether changes in fish intake in mid/later life is associated with risk [17 ]. The authors observed that increasing fish consumption to at least two servings per week was associated with a lower CHD risk in women but not in men [17 ]. By specifying hypothetical interventions, this study significantly adds evidence to earlier observational studies, which largely focused on effects of lifelong eating habits. Still, as this study was not a randomized controlled trial, the possibility that confounding partly explained the results cannot be excluded. Finally, the multiethnic MESA study has addressed the question whether the association of seafood-derived long-chain n-3 PUFAs with risk of cardiovascular disease (CVD) depends on ethnicity, as suggested for type 2 diabetes [6–8,10,11]. Of note, &
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www.co-lipidology.com
Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbru¨cke, Nuthetal, Germany Correspondence to Janine Kro¨ger, Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbru¨cke, ArthurScheunert-Allee 114-116, 14558 Nuthetal, Germany. Tel: +49 (0)33200 88 2431; fax: +49 (0)33200 88 2437; e-mail: [email protected] Curr Opin Lipidol 2014, 25:228–229 DOI:10.1097/MOL.0000000000000078 Volume 25 Number 3 June 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Bimonthly update Dietary fish intake and the risk for type 2 diabetes and cardiovascular disease
the inverse associations of EPA and DHA with CVD risk were present across different ethnicities (here: whites, Hispanics, African-Americans, Chinese-Americans) in MESA [18 ]. Despite these advances in the understanding of the role of intake of fish and long-chain n-3 PUFAs for risk of type 2 diabetes and CVD, some questions still remain unanswered. Future studies should evaluate differences between study locations regarding the association with diabetes risk, taking into consideration types of fish consumed as well as preparation methods, which may be country-specific. Furthermore, contamination of fish (e.g. with mercury) may further contribute to differences between studies and should be explored further. &
Acknowledgements None. Conflicts of interest There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. He K. Fish, long-chain omega-3 polyunsaturated fatty acids and prevention of cardiovascular disease–eat fish or take fish oil supplement? Prog Cardiovasc Dis 2009; 52:95–114. 2. Rizos EC, Ntzani EE, Bika E, et al. Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. JAMA 2012; 308:1024–1033. 3. Akinkuolie AO, Ngwa JS, Meigs JB, Djousse´ L. Omega-3 polyunsaturated fatty acid and insulin sensitivity: a meta-analysis of randomized controlled trials. Clin Nutr 2011; 30:702–707. 4. He K, Song Y, Daviglus ML, et al. Accumulated evidence on fish consumption and coronary heart disease mortality: a meta-analysis of cohort studies. Circulation 2004; 109:2705–2711.
5. Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA 2006; 296:1885–1899. 6. Wallin A, Di Giuseppe D, Orsini N, et al. Fish consumption, dietary long-chain n-3 fatty acids, and risk of type 2 diabetes: systematic review and metaanalysis of prospective studies. Diabetes Care 2012; 35:918–929. 7. Xun P, He K. Fish Consumption and Incidence of Diabetes: meta-analysis of data from 438,000 individuals in 12 independent prospective cohorts with an average 11-year follow-up. Diabetes Care 2012; 35:930–938. 8. Wu JH, Micha R, Imamura F, et al. Omega-3 fatty acids and incident type 2 diabetes: a systematic review and meta-analysis. Br J Nutr 2012; 107 (Suppl 2):S214–227. 9. Zhou Y, Tian C, Jia C. Association of fish and n-3 fatty acid intake with the risk of type 2 diabetes: a meta-analysis of prospective studies. Br J Nutr 2012; 108:408–417. 10. Zheng JS, Huang T, Yang J, et al. Marine N-3 polyunsaturated fatty acids are inversely associated with risk of type 2 diabetes in Asians: a systematic review and meta-analysis. PLoS One 2012; 7:e44525. 11. Zhang M, Picard-Deland E, Marette A. Fish and marine omega-3 polyunsatured fatty acid consumption and incidence of type 2 diabetes: a systematic review and meta-analysis. Int J Endocrinol 2013; 2013:501015. 12. Mahendran Y, Agren J, Uusitupa M, et al. Association of erythrocyte mem& brane fatty acids with changes in glycemia and risk of type 2 diabetes. Am J Clin Nutr 2014; 99:79–85. This is the first study that prospectively evaluated blood proportions of fatty acids in relation to insulin sensitivity and insulin secretion, which may be mechanisms explaining the relation of fatty acids with incident diabetes. 13. Mahendran Y, Cederberg H, Vangipurapu J, et al. Glycerol and fatty acids in serum predict the development of hyperglycemia and type 2 diabetes in Finnish men. Diabetes Care 2013; 36:3732–3738. 14. Virtanen JK, Mursu J, Voutilainen S, et al. Serum omega-3 polyunsaturated & Fatty acids and risk of incident type 2 diabetes in men: the kuopio ischemic heart disease risk factor study. Diabetes Care 2014; 37:189–196. This is comprehensive analysis considering blood proportions of PUFAs, dietary intake data of fish and PUFAs as well as the mercury content of hair. Furthermore, the authors were able to use data from a very long follow-up period (average followup of 19 years). 15. He K, Xun P, Liu K, et al. Mercury exposure in young adulthood and incidence & of diabetes later in life: the CARDIA Trace Element Study. Diabetes Care 2013; 36:1584–1589. In this study, the prospective association of mercury exposure with diabetes risk was investigated for the first time. 16. Mozaffarian D, Shi P, Morris JS, et al. Methylmercury exposure and incident diabetes in U.S. men and women in two prospective cohorts. Diabetes Care 2013; 36:3578–3584. 17. Lajous M, Willett WC, Robins J, et al. Changes in fish consumption in midlife & and the risk of coronary heart disease in men and women. Am J Epidemiol 2013; 178:382–391. By applying appropriate statistical methods, this study investigated hypothetical dietary interventions to evaluate the effectiveness of changes in fish intake in mid or later life. 18. de Oliveira Otto MC, Wu JH, Baylin A, et al. Circulating and dietary omega-3 & and omega-6 polyunsaturated fatty acids and incidence of CVD in the multiethnic study of atherosclerosis. J Am Heart Assoc 2013; 2:e000506. This is the first study that compared associations of blood contents of n-3 and n-6 PUFAs with incidence of CVD across different racial-ethnic groups (whites, Hispanics, African Americans, Chinese Americans).
0957-9672 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
www.co-lipidology.com
229
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
URRENT C OPINION Current Opinion in Lipidology
Bimonthly update This section provides a rapid update service, covering the whole field of lipidology, and lists papers entered into the publisher’s database from OvidSP.
Contents
Key articles are selected for comment by specialists and are highlighted in the following way:
228 Dietary fish intake and the risk for type 2 diabetes and cardiovascular disease: new insights Janine Kro¨ger and Matthias B. Schulze
Papers considered to be of specialist interest Papers considered to be of outstanding interest A bibliographic listing follows each comment and selected papers are accompanied by an annotation in which the scope and context of the article are summarized briefly.
Edited by Alan Rees
230 High-density lipoproteins: taking the good with the bad Charles E. Sparks, James P. Corsetti and Janet D. Sparks 233 Bariatric surgery and cardiovascular risk reduction Laxmi Narsimha Rao Bondugulapati, Vinay S. Eligar and Alan Rees
Current Opinion in Lipidology 2014, 25:228–238 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins 0957-9672
235 Atherosclerosis: cell biology and lipoproteins epigenetics and oxidation in atherosclerosis Silvio Zaina and Gertrud Lund 237 Management of homozygous familial hypercholesterolaemia Vinay S. Eligar, Laxmi N.R. Bondugulapati and Alan Rees
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
EDITORIAL COMMENT URRENT C OPINION
Dietary fish intake and the risk for type 2 diabetes and cardiovascular disease: new insights Janine Kro¨ger and Matthias B. Schulze
Current dietary guidelines emphasize regular consumption of fish, with at least two servings of fish per week, one of which should be sea fish. Longchain n-3 polyunsaturated fatty acids (PUFAs), mainly found in fatty fish, have been attributed beneficial effects on cardiovascular risk factors like vascular resistance, inflammation and blood lipids [1]. Trials with fish oil supplements resulted in lower coronary heart disease (CHD) mortality [2], whereas no clear benefit was observed on glucose-insulin homeostasis [3]; however, results were mixed. As no long-term trials have been conducted yet, large observational studies with long follow-up could provide valuable insight. In prospective observational studies, fish intake was associated with lower CHD risk and CHD mortality [4,5]. As for type 2 diabetes, there was no clear association of intakes of fish or eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) with risk in recent meta-analyses [6–11]. However, results of the original studies were mixed and there was significant heterogeneity based on the geographical region of the study population (inverse association in Asian/Australian populations, no association in European populations, direct association in US populations). The purpose of this article is to summarize the most important findings from observational studies published during the last year. Only recently, three new articles on blood proportions of long-chain n-3 PUFAs and diabetes risk have been published. In the Finnish METSIM study with 5-year follow-up, neither erythrocyte EPA and DHA [12 ] nor serum DHA [13], which are regarded as biomarkers of intake, showed a significant association with diabetes risk. Of note, there was also no significant association of these biomarkers with insulin sensitivity or secretion at 5-year follow-up, which is a novel finding. Virtanen et al. [14 ] analyzed data of another Finnish cohort with 19 years of follow-up and observed inverse associations for serum long-chain n-3 PUFAs; however, results were not significant for EPA. Reasons for these divergent findings are unknown. Duration of follow-up seems an unlikely explanation here because the detection of inverse associations has been associated with &
short follow-up periods in recent meta-analyses [7,8]. Fish and seafood products are the major dietary sources of mercury accumulation in the body, which was related to b-cell function in experimental models. During the last year, the first studies relating biomarkers of mercury exposure to diabetes incidence have emerged. In the CARDIA study, toenail mercury levels were positively associated with diabetes risk after adjustment for long-chain n-3 PUFAs [15 ]. However, this was not confirmed by analyses of the Health Professionals Follow-Up Study (HPFS) and the Nurses’ Health Study (NHS) [16]. Virtanen et al. [14 ] also did not observe a significant relation for hair mercury; however, no adjustment for longchain n-3 PUFAs was made. Given these inconsistent findings, further studies should explore the role of mercury exposure for diabetes risk. As for CHD, an interesting analysis of the HPFS and the NHS has been published recently addressing the relevant question whether changes in fish intake in mid/later life is associated with risk [17 ]. The authors observed that increasing fish consumption to at least two servings per week was associated with a lower CHD risk in women but not in men [17 ]. By specifying hypothetical interventions, this study significantly adds evidence to earlier observational studies, which largely focused on effects of lifelong eating habits. Still, as this study was not a randomized controlled trial, the possibility that confounding partly explained the results cannot be excluded. Finally, the multiethnic MESA study has addressed the question whether the association of seafood-derived long-chain n-3 PUFAs with risk of cardiovascular disease (CVD) depends on ethnicity, as suggested for type 2 diabetes [6–8,10,11]. Of note, &
&
&
&
&
www.co-lipidology.com
Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbru¨cke, Nuthetal, Germany Correspondence to Janine Kro¨ger, Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbru¨cke, ArthurScheunert-Allee 114-116, 14558 Nuthetal, Germany. Tel: +49 (0)33200 88 2431; fax: +49 (0)33200 88 2437; e-mail: [email protected] Curr Opin Lipidol 2014, 25:228–229 DOI:10.1097/MOL.0000000000000078 Volume 25 Number 3 June 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Bimonthly update Dietary fish intake and the risk for type 2 diabetes and cardiovascular disease
the inverse associations of EPA and DHA with CVD risk were present across different ethnicities (here: whites, Hispanics, African-Americans, Chinese-Americans) in MESA [18 ]. Despite these advances in the understanding of the role of intake of fish and long-chain n-3 PUFAs for risk of type 2 diabetes and CVD, some questions still remain unanswered. Future studies should evaluate differences between study locations regarding the association with diabetes risk, taking into consideration types of fish consumed as well as preparation methods, which may be country-specific. Furthermore, contamination of fish (e.g. with mercury) may further contribute to differences between studies and should be explored further. &
Acknowledgements None. Conflicts of interest There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. He K. Fish, long-chain omega-3 polyunsaturated fatty acids and prevention of cardiovascular disease–eat fish or take fish oil supplement? Prog Cardiovasc Dis 2009; 52:95–114. 2. Rizos EC, Ntzani EE, Bika E, et al. Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. JAMA 2012; 308:1024–1033. 3. Akinkuolie AO, Ngwa JS, Meigs JB, Djousse´ L. Omega-3 polyunsaturated fatty acid and insulin sensitivity: a meta-analysis of randomized controlled trials. Clin Nutr 2011; 30:702–707. 4. He K, Song Y, Daviglus ML, et al. Accumulated evidence on fish consumption and coronary heart disease mortality: a meta-analysis of cohort studies. Circulation 2004; 109:2705–2711.
5. Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA 2006; 296:1885–1899. 6. Wallin A, Di Giuseppe D, Orsini N, et al. Fish consumption, dietary long-chain n-3 fatty acids, and risk of type 2 diabetes: systematic review and metaanalysis of prospective studies. Diabetes Care 2012; 35:918–929. 7. Xun P, He K. Fish Consumption and Incidence of Diabetes: meta-analysis of data from 438,000 individuals in 12 independent prospective cohorts with an average 11-year follow-up. Diabetes Care 2012; 35:930–938. 8. Wu JH, Micha R, Imamura F, et al. Omega-3 fatty acids and incident type 2 diabetes: a systematic review and meta-analysis. Br J Nutr 2012; 107 (Suppl 2):S214–227. 9. Zhou Y, Tian C, Jia C. Association of fish and n-3 fatty acid intake with the risk of type 2 diabetes: a meta-analysis of prospective studies. Br J Nutr 2012; 108:408–417. 10. Zheng JS, Huang T, Yang J, et al. Marine N-3 polyunsaturated fatty acids are inversely associated with risk of type 2 diabetes in Asians: a systematic review and meta-analysis. PLoS One 2012; 7:e44525. 11. Zhang M, Picard-Deland E, Marette A. Fish and marine omega-3 polyunsatured fatty acid consumption and incidence of type 2 diabetes: a systematic review and meta-analysis. Int J Endocrinol 2013; 2013:501015. 12. Mahendran Y, Agren J, Uusitupa M, et al. Association of erythrocyte mem& brane fatty acids with changes in glycemia and risk of type 2 diabetes. Am J Clin Nutr 2014; 99:79–85. This is the first study that prospectively evaluated blood proportions of fatty acids in relation to insulin sensitivity and insulin secretion, which may be mechanisms explaining the relation of fatty acids with incident diabetes. 13. Mahendran Y, Cederberg H, Vangipurapu J, et al. Glycerol and fatty acids in serum predict the development of hyperglycemia and type 2 diabetes in Finnish men. Diabetes Care 2013; 36:3732–3738. 14. Virtanen JK, Mursu J, Voutilainen S, et al. Serum omega-3 polyunsaturated & Fatty acids and risk of incident type 2 diabetes in men: the kuopio ischemic heart disease risk factor study. Diabetes Care 2014; 37:189–196. This is comprehensive analysis considering blood proportions of PUFAs, dietary intake data of fish and PUFAs as well as the mercury content of hair. Furthermore, the authors were able to use data from a very long follow-up period (average followup of 19 years). 15. He K, Xun P, Liu K, et al. Mercury exposure in young adulthood and incidence & of diabetes later in life: the CARDIA Trace Element Study. Diabetes Care 2013; 36:1584–1589. In this study, the prospective association of mercury exposure with diabetes risk was investigated for the first time. 16. Mozaffarian D, Shi P, Morris JS, et al. Methylmercury exposure and incident diabetes in U.S. men and women in two prospective cohorts. Diabetes Care 2013; 36:3578–3584. 17. Lajous M, Willett WC, Robins J, et al. Changes in fish consumption in midlife & and the risk of coronary heart disease in men and women. Am J Epidemiol 2013; 178:382–391. By applying appropriate statistical methods, this study investigated hypothetical dietary interventions to evaluate the effectiveness of changes in fish intake in mid or later life. 18. de Oliveira Otto MC, Wu JH, Baylin A, et al. Circulating and dietary omega-3 & and omega-6 polyunsaturated fatty acids and incidence of CVD in the multiethnic study of atherosclerosis. J Am Heart Assoc 2013; 2:e000506. This is the first study that compared associations of blood contents of n-3 and n-6 PUFAs with incidence of CVD across different racial-ethnic groups (whites, Hispanics, African Americans, Chinese Americans).
0957-9672 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
www.co-lipidology.com
229
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
