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Systematic Reviews
Published in: Systematic Reviews 1/2018

Open Access 01-12-2018 | Protocol

Modifiable and emerging risk factors for type 2 diabetes in Africa: a systematic review and meta-analysis protocol

Authors: Ayuba Issaka, Yin Paradies, Christopher Stevenson

Published in: Systematic Reviews | Issue 1/2018

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Abstract

Background

Type 2 diabetes mellitus (T2DM) remains a public health problem in low-income countries, including African countries. Risk factors of this disease in Africa are still unclear. This study will examine the modifiable and emerging risk factors associated with T2DM in Africa.

Methodology

The study will include a systematic review and meta-analysis of published and unpublished empirical studies, reporting quantitative data only. We will conduct a search on scientific databases (e.g. Global Health), general online search engines (e.g. Google Scholar) and key websites for grey literature using a combination of key countries/geographic terms, risk factors (e.g. overweight/obesity) and T2DM (including a manual search of the included reference lists). We will use the Comprehensive Meta-Analysis Software (CMA) version 2.0 for data management and analysis. This protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P).

Discussion

The systematic review and meta-analysis will provide a robust and reliable evidence base for policy makers and future research. This may help with identifying and implementing more cost-effective diabetes prevention strategies and improved resource allocation.

Systematic review registration

This protocol has been registered with the PROSPERO international prospective register of systematic reviews. The reference number is CRD42016043027.
Appendix
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Literature
1.
Renzaho AMN. The post-2015 development agenda for diabetes in Sub-Saharan Africa: challenges and future directions. Glob Health Action. 2015;8:–27600.
2.
Romdhane HB, Ali SB, Aissi W, Traissac P, Aounallah-Skhiri H, Bougatef S, Maire B, Delpeuch F, Achour N. Prevalence of diabetes in Northern African countries: the case of Tunisia. BMC Public Health. 2014;14:86.CrossRefPubMedPubMedCentral
3.
4.
Kirigia JM, Sambo HB, Sambo LG, Barry SP. Economic burden of diabetes mellitus in the WHO African region. BMC Int Health Hum Rights. 2009;9:1–12.CrossRef
5.
6.
Peer N, Kengne A-P, Motala AA, Mbanya JC. Diabetes in the Africa region: an update. Diabetes Res Clin Pract. 2014;103:197–205.CrossRefPubMed
7.
Seck SM, Dia DG, Doupa D, Diop-Dia A, Thiam I, Ndong M, Gueye L. Diabetes burden in urban and rural Senegalese populations: a cross-sectional study in 2012. Int J Endocrinol. 2015;2015:1–6.CrossRef
8.
Kengne AP, Echouffo-Tcheugui J-B, Sobngwi E, Mbanya J-C. New insights on diabetes mellitus and obesity in Africa-part 1: prevalence, pathogenesis and comorbidities. Heart. 2013;99:979–83.CrossRefPubMed
9.
Lozano R, Naghavi M, Foreman K, Lim S, Shibuya K, Aboyans V, Abraham J, Adair T, Aggarwal R, Ahn SY. Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the global burden of disease study 2010. Lancet. 2013;380:2095–128.CrossRef
10.
Murray CJ, Vos T, Lozano R, Naghavi M, Flaxman AD, Michaud C, Ezzati M, Shibuya K, Salomon JA, Abdalla S. Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990–2010: a systematic analysis for the global burden of disease study 2010. Lancet. 2013;380:2197–223.CrossRef
11.
Murray CJ, Lopez AD. Mortality by cause for eight regions of the world: global burden of disease study. Lancet. 1997;349:1269–76.CrossRefPubMed
12.
Kengne AP, Amoah AG, Mbanya J-C. Cardiovascular complications of diabetes mellitus in Sub-Saharan Africa. Circulation. 2005;112:3592–601.CrossRefPubMed
13.
Yach D, Hawkes C, Gould CL, Hofman KJ. The global burden of chronic diseases: overcoming impediments to prevention and control. Jama. 2004;291:2616–22.CrossRefPubMed
14.
BeLue R, Okoror TA, Iwelunmor J, Taylor KD, Degboe AN, Agyemang C, Ogedegbe G. An overview of cardiovascular risk factor burden in Sub-Saharan African countries: a socio-cultural perspective. Glob Health. 2009;5:10.CrossRef
15.
Hall V, Thomsen RW, Henriksen O, Lohse N. Diabetes in Sub-Saharan Africa 1999-2011: epidemiology and public health implications. A systematic review. BMC Public Health. 2011;11:564.CrossRefPubMedPubMedCentral
16.
Tuei VC, Maiyoh GK, Ha CE. Type 2 diabetes mellitus and obesity in sub-Saharan Africa. Diabetes Metab Res Rev. 2010;26:433–45.CrossRefPubMed
17.
Beaglehole R, Bonita R, Horton R, Adams C, Alleyne G, Asaria P, Baugh V, Bekedam H, Billo N, Casswell S. Priority actions for the non-communicable disease crisis. Lancet. 2011;377:1438–47.CrossRefPubMed
18.
Werfalli M, Engel ME, Musekiwa A, Kengne AP, Levitt NS. The prevalence of type 2 diabetes among older people in Africa: a systematic review. Lancet Diabetes Endocrinol. 2016;4:72–84.CrossRefPubMed
19.
Sobngwi E, Mauvais-Jarvis F, Vexiau P, Mbanya J, Gautier J. Diabetes in Africans. Part 1: epidemiology and clinical specificities. Diabetes Metab. 2001;27:628–34.PubMed
20.
21.
Unwin N, Setel P, Rashid S, Mugusi F, Mbanya J-C, Kitange H, Hayes L, Edwards R, Aspray T, Alberti K. Noncommunicable diseases in Sub-Saharan Africa: where do they feature in the health research agenda? Bull World Health Organ. 2001;79:947–53.PubMedPubMedCentral
22.
Levitt NS. Diabetes in Africa: epidemiology, management and healthcare challenges. Heart. 2008;94:1376–82.CrossRefPubMed
23.
24.
Popkin BM, Horton S, Kim S, Mahal A, Shuigao J. Trends in diet, nutritional status, and diet-related noncommunicable diseases in China and India: the economic costs of the nutrition transition. Nutr Rev. 2001;59:379–90.CrossRefPubMed
25.
de Munter JS, Hu FB, Spiegelman D, Franz M, van Dam RM. Whole grain, bran, and germ intake and risk of type 2 diabetes: a prospective cohort study and systematic review. PLoS Med. 2007;4:e261.CrossRefPubMedPubMedCentral
26.
Frank LK, Kröger J, Schulze MB, Bedu-Addo G, Mockenhaupt FP, Danquah I. Dietary patterns in urban Ghana and risk of type 2 diabetes. Br J Nutr. 2014;112:89–98.CrossRefPubMed
27.
Ekpenyong C, Udokang N, Akpan E, Samson T. Double burden, non-communicable diseases and risk factors evaluation in Sub-Saharan Africa: the Nigerian experience. Eur J Sustainable Dev. 2012;1:249.
28.
Hegazi R, El-Gamal M, Abdel-Hady N, Hamdy O. Epidemiology of and risk factors for type 2 diabetes in Egypt. Ann Global Health. 2015;81:814–20.CrossRef
29.
Hu FB, Manson JE, Stampfer MJ, Colditz G, Liu S, Solomon CG, Willett WC. Diet, lifestyle, and the risk of type 2 diabetes mellitus in women. N Engl J Med. 2001;345:790–7.CrossRefPubMed
30.
Maiyaki MB, Garbati MA. The burden of non-communicable diseases in Nigeria; in the context of globalization. Ann Afr Med. 2014;13:1–10.CrossRefPubMed
31.
Pitcher A. Lions, tigers, and emerging markets: Africa’s development dilemmas. Current History. 2012;111:163.
32.
Wojcicki JM, Heyman MB. Malnutrition and the role of the soft drink industry in improving child health in Sub-Saharan Africa. Pediatrics. 2010;126:e1617–21.CrossRefPubMedPubMedCentral
33.
Basu S, McKee M, Galea G, Stuckler D. Relationship of soft drink consumption to global overweight, obesity, and diabetes: a cross-national analysis of 75 countries. Am J Public Health. 2013;103:2071–7.CrossRefPubMedPubMedCentral
34.
Peer N, Steyn K, Lombard C, Lambert EV, Vythilingum B, Levitt NS. Rising diabetes prevalence among urban-dwelling black South Africans. PLoS One. 2012;7:e43336.CrossRefPubMedPubMedCentral
35.
Rasmussen M, Krølner R, Klepp K-I, Lytle L, Brug J, Bere E, Due P. Determinants of fruit and vegetable consumption among children and adolescents: a review of the literature. Part I: quantitative studies. Int J Behav Nutr Phys Act. 2006;3:1.CrossRef
36.
Shimokata H, Muller DC, Andres R. Studies in the distribution of body fat: III. Effects of cigarette smoking. Jama. 1989;261:1169–73.CrossRefPubMed
37.
Barrett-Connor E, Khaw K-T. Cigarette smoking and increased central adiposity. Ann Intern Med. 1989;111:783–7.CrossRefPubMed
38.
Melikian AA, Hoffmann D. Smokeless tobacco: a gateway to smoking or a way away from smoking. Biomarkers. 2009;14:85–9.CrossRefPubMed
39.
40.
41.
Willi C, Bodenmann P, Ghali WA, Faris PD, Cornuz J. Active smoking and the risk of type 2 diabetes: a systematic review and meta-analysis. Jama. 2007;298:2654–64.CrossRefPubMed
42.
World Health Organization. WHO report on the global tobacco epidemic, 2013: enforcing bans on tobacco advertising, promotion and sponsorship. Geneva: World Health Organization; 2013.
43.
44.
Townsend L, Flisher AJ, Gilreath T, King G. A systematic literature review of tobacco use among adults 15 years and older in Sub-Saharan Africa. Drug Alcohol Depend. 2006;84:14–27.CrossRefPubMed
45.
Jha P, Ranson MK, Nguyen SN, Yach D. Estimates of global and regional smoking prevalence in 1995, by age and sex. Am J Public Health. 2002;92:1002–6.CrossRefPubMedPubMedCentral
46.
Sreeramareddy CT, Pradhan PM, Sin S. Prevalence, distribution, and social determinants of tobacco use in 30 Sub-Saharan African countries. BMC Med. 2014;12:243.CrossRefPubMedPubMedCentral
47.
Bissessur S, Naidoo S. Areca nut and tobacco chewing habits in Durban, KwaZulu Natal. SADJ. 2009;64:460–3.PubMed
48.
Howard AA, Arnsten JH, Gourevitch MN. Effect of alcohol consumption on diabetes mellitus: a systematic review. Ann Intern Med. 2004;140:211–9.CrossRefPubMed
49.
Puepet F, Ohwovoriole A. Prevalence of risk factors for diabetes mellitus in a non-diabetic population in Jos, Nigeria. Niger J Med. 2008;17:71–4.CrossRefPubMed
50.
Christensen DL, Friis H, Mwaniki D, Kilonzo B, Tetens I, Boit M, Omondi B, Kaduka L, Borch-Johnsen K. Prevalence of glucose intolerance and associated risk factors in rural and urban populations of different ethnic groups in Kenya. Diabetes Res Clin Pract. 2009;84:303–10.CrossRefPubMed
51.
Motala AA, Esterhuizen T, Gouws E, Pirie FJ, Omar MA. Diabetes and other disorders of glycemia in a rural South African community prevalence and associated risk factors. Diabetes Care. 2008;31:1783–8.CrossRefPubMedPubMedCentral
52.
Nyenwe EA, Odia OJ, Ihekwaba AE, Ojule A, Babatunde S. Type 2 diabetes in adult Nigerians: a study of its prevalence and risk factors in Port Harcourt, Nigeria. Diabetes Res Clin Pract. 2003;62:177–85.CrossRefPubMed
53.
Motala AA, Esterhuizen T, Gouws E, Pirie FJ, Omar MA. Diabetes and other disorders of glycemia in a rural South African community. Diabetes Care. 2008;31:1783–8.CrossRefPubMedPubMedCentral
54.
Christensen DL. Glucose intolerance in relation to body composition, physical activity and other predictors among the Luo, Kamba and Maasai of Kenya [PhD Thesis]. Copenhagen: University of Copenhagen, 2009.
55.
Etukumana EA, Puepet FH, Obadofin MO. Risk factors for diabetes mellitus among rural adults in Nigeria. Nig J Med. 2014;23:213–9.
56.
Mayige M, Kagaruki G, Ramaiya K, Swai A. Non communicable diseases in Tanzania: a call for urgent action. Tanzania J Health Res.2012;14:1–12.
57.
Parry CD, Myers B, Morojele NK, Flisher AJ, Bhana A, Donson H, Plüddemann A. Trends in adolescent alcohol and other drug use: findings from three sentinel sites in South Africa (1997–2001). J Adolesc. 2004;27:429–40.CrossRefPubMed
58.
Obot IS. Alcohol use and related problems in Sub-Saharan Africa. Afr J Drug Alcohol Stud. 2006;5:17–26.
59.
Obot IS. The measurement of drinking patterns and alcohol problems in Nigeria. J Subst Abus. 2000;12:169–81.CrossRef
60.
61.
62.
Assah FK. Physical activity, cardiorespiratory fitness and metabolic health in Cameroon. PhD Thesis, University of Cambridge. 2010.
63.
Niakara A, Fournet F, Gary J, Harang M, Nébié LV, Salem G. Hypertension, urbanization, social and spatial disparities: a cross-sectional population-based survey in a West African urban environment (Ouagadougou, Burkina Faso). Trans R Soc Trop Med Hyg. 2007;101:1136–42.CrossRefPubMed
64.
Sobngwi E, Mbanya J-C, Unwin NC, Porcher R, Kengne A-P, Fezeu L, Minkoulou EM, Tournoux C, Gautier J-F, Aspray TJ. Exposure over the life course to an urban environment and its relation with obesity, diabetes, and hypertension in rural and urban Cameroon. Int J Epidemiol. 2004;33:769–76.CrossRefPubMed
65.
Malan L, Malan NT, Wissing MP, Seedat YK. Coping with urbanization: a cardiometabolic risk?: the THUSA study. Biol Psychol. 2008;79:323–8.CrossRefPubMed
66.
Kaufman JS, Owoaje EE, James SA, Rotimi CN, Cooper RS. Determinants of hypertension in West Africa: contribution of anthropometric and dietary factors to urban-rural and socioeconomic gradients. Am J Epidemiol. 1996;143:1203–18.CrossRefPubMed
67.
Mbanya JCN, Motala AA, Sobngwi E, Assah FK, Enoru ST. Diabetes in Sub-Saharan Africa. Lancet. 2010;375:2254–66.CrossRefPubMed
68.
Pittas AG, Dawson-Hughes B, Li T, Van Dam RM, Willett WC, Manson JE, Hu FB. Vitamin D and calcium intake in relation to type 2 diabetes in women. Diabetes Care. 2006;29:650–6.CrossRefPubMed
69.
Peer N, Steyn K, Lombard C, Gwebushe N, Levitt N. A high burden of hypertension in the urban black population of Cape Town: the cardiovascular risk in black South Africans (CRIBSA) study. PLoS One. 2013;8:e78567.CrossRefPubMedPubMedCentral
70.
Assah FK, Ekelund U, Brage S, Corder K, Wright A, Mbanya JC, Wareham NJ. Predicting physical activity energy expenditure using accelerometry in adults from Sub-Sahara Africa. Obesity. 2009;17:1588–95.CrossRefPubMed
71.
Fezeu LK, Assah FK, Balkau B, Mbanya DS, Kengne AP, Awah PK, Mbanya JCN. Ten-year changes in central obesity and BMI in rural and urban Cameroon. Obesity. 2008;16:1144–7.CrossRefPubMed
72.
Tesfaye F, Byass P, Wall S. Population based prevalence of high blood pressure among adults in Addis Ababa: uncovering a silent epidemic. BMC Cardiovasc Disord. 2009;9:39.CrossRefPubMedPubMedCentral
73.
Longo-Mbenza B, Mambune H, Kasiam J, Vita E, Fuele S, Nsenga J, Mabwa L, Nzuzi V. Relationship between waist circumference and cholesterol in Central Africans with congestive heart failure. West Afr J Med. 2006;26:183–90.
74.
Hill AG, Darko R, Seffah J, Adanu RM, Anarfi JK, Duda RB. Health of urban Ghanaian women as identified by the Women's Health Study of Accra. Int J Gynecol Obstet. 2007;99:150–6.CrossRef
75.
Steyn NP, McHiza ZJ. Obesity and the nutrition transition in Sub-Saharan Africa. Ann N Y Acad Sci. 2014;1311:88–101.CrossRefPubMed
76.
Fisch A, Pichard E, Prazuck T, Leblanc H, Sidibe Y, Brücker G. Prevalence and risk factors of diabetes mellitus in the rural region of Mali (West Africa): a practical approach. Diabetologia. 1987;30:859–62.PubMed
77.
Elbagir M, Eltom M, Elmahadi E, Kadam I, Berne C. A high prevalence of diabetes mellitus and impaired glucose tolerance in the Danagla community in northern Sudan. Diabet Med. 1998;15:164–9.CrossRefPubMed
78.
Elbagir MN, Eltom MA, Elmahadi EM, Kadam IM, Berne C. A population-based study of the prevalence of diabetes and impaired glucose tolerance in adults in northern Sudan. Diabetes Care. 1996;19:1126–8.CrossRefPubMed
79.
Aspray TJ, Mugusi F, Rashid S, Whiting D, Edwards R, Alberti KG, Unwin NC, Project EN-CDHI. Rural and urban differences in diabetes prevalence in Tanzania: the role of obesity, physical inactivity and urban living. Trans R Soc Trop Med Hyg. 2000;94:637–44.CrossRefPubMed
80.
Baldé N-M, Diallo I, Baldé M-D, Barry I-S, Kaba L, Diallo M-M, Kaké A, Camara A, Bah D, Barry M-M. Diabetes and impaired fasting glucose in rural and urban populations in Futa Jallon (Guinea): prevalence and associated risk factors. Diabetes Metab. 2007;33:114–20.CrossRefPubMed
81.
82.
Kyari F, Tafida A, Sivasubramaniam S, Murthy GV, Peto T, Gilbert CE. Prevalence and risk factors for diabetes and diabetic retinopathy: results from the Nigeria national blindness and visual impairment survey. BMC Public Health. 2014;14:1299.CrossRefPubMedPubMedCentral
83.
Levitt N, Steyn K, Lambert E, Reagon G, Lombard C, Fourie J, Rossouw K, Hoffman M. Modifiable risk factors for type 2 diabetes mellitus in a peri-urban community in South Africa. Diabet Med. 1999;16:946–50.CrossRefPubMed
84.
Chen L, Magliano DJ, Zimmet PZ. The worldwide epidemiology of type 2 diabetes mellitus—present and future perspectives. Nat Rev Endocrinol. 2012;8:228–36.CrossRef
85.
Chandola T. Chronic stress at work and the metabolic syndrome: prospective study. Med Benefits. 2006;23:3–3.
86.
Wong ND, Rozanski A, Gransar H, Miranda-Peats R, Kang X, Hayes S, Shaw L, Friedman J, Polk D, Berman DS. Metabolic syndrome and diabetes are associated with an increased likelihood of inducible myocardial ischemia among patients with subclinical atherosclerosis. Diabetes Care. 2005;28:1445–50.CrossRefPubMed
87.
Coyne T, Ibiebele TI, Baade PD, CS MC, Shaw JE. Metabolic syndrome and serum carotenoids: findings of a cross-sectional study in Queensland, Australia. Br J Nutr. 2009;102:1668–77.CrossRefPubMed
88.
Chida Y, Hamer M. An association of adverse psychosocial factors with diabetes mellitus: a meta-analytic review of longitudinal cohort studies. Diabetologia 2008; 51:2168–178.
89.
Abubakari A-R, Bhopal R. Systematic review on the prevalence of diabetes, overweight/obesity and physical inactivity in Ghanaians and Nigerians. Public Health. 2008;122:173–82.CrossRefPubMed
90.
Werfalli M, Musekiwa A, Engel ME, Ross I, Kengne AP, Levitt NS. The prevalence of type 2 diabetes mellitus among older people in Africa: a systematic review study protocol. BMJ Open. 2014;4:e004747.CrossRefPubMedPubMedCentral
91.
Hilawe EH, Yatsuya H, Kawaguchi L, Aoyama A. Differences by sex in the prevalence of diabetes mellitus, impaired fasting glycaemia and impaired glucose tolerance in Sub-Saharan Africa: a systematic review and meta-analysis. Bull World Health Organ. 2013;91:671–682D.CrossRefPubMedPubMedCentral
92.
Mutowo M, Gowda U, Mangwiro JC, Lorgelly P, Owen A, Renzaho A. Prevalence of diabetes in Zimbabwe: a systematic review with meta-analysis. Int J Public Health. 2015;60:1–11.CrossRefPubMed
93.
94.
Burgess P, MacCormick I, Harding S, Bastawrous A, Beare N, Garner P. Epidemiology of diabetic retinopathy and maculopathy in Africa: a systematic review. Diabet Med. 2013;30:399–412.CrossRefPubMedPubMedCentral
95.
Neilson HK, Robson PJ, Friedenreich CM, Csizmadi I. Estimating activity energy expenditure: how valid are physical activity questionnaires? Am J Clin Nutr. 2008;87:279–91.CrossRefPubMed
96.
Singh J, Prentice A, Diaz E, Coward W, Ashford J, Sawyer M, Whitehead R. Energy expenditure of Gambian women during peak agricultural activity measured by the doubly-labelled water method. Br J Nutr. 1989;62:315–29.CrossRefPubMed
97.
CASP U. Critical Appraisal Skills Programme. Randomised Controlled Trail Checklist Zugriff am. 2013;18:2015.
98.
Stang A. Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses. Eur J Epidemiol. 2010;25:603–5.CrossRefPubMed
99.
100.
101.
102.
Pieterse AL, Todd NR, Neville HA, Carter RT. Perceived racism and mental health among Black American adults: a meta-analytic review. J Couns Psychol. 2012;59:1.CrossRefPubMed
103.
104.
Huedo-Medina TB, Sánchez-Meca J, Marín-Martínez F, Botella J. Assessing heterogeneity in meta-analysis: Q statistic or I2 index? Psychol Methods. 2006;11:193.CrossRefPubMed
105.
Paradies Y, Priest N, Ben J, Truong M, Gupta A, Pieterse A, Kelaher M, Gee G. Racism as a determinant of health: a protocol for conducting a systematic review and meta-analysis. Syst Rev. 2013;2:1.CrossRef
Metadata
Title
Modifiable and emerging risk factors for type 2 diabetes in Africa: a systematic review and meta-analysis protocol
Authors
Ayuba Issaka
Yin Paradies
Christopher Stevenson
Publication date
01-12-2018
Publisher
BioMed Central
Published in
Systematic Reviews / Issue 1/2018
Electronic ISSN: 2046-4053
DOI
https://doi.org/10.1186/s13643-018-0801-y

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