This qualitative study explored lifestyle-related factors influencing T2DM management among Tongan adults residing in the Kingdom of Tonga. Participants in our study had very little knowledge of the aetiology of T2DM prior to their diagnosis a finding that has been reported previously [29, 30, 31]. They acknowledged receipt of education through the hospital’s specialist clinic, and how important this was, once they knew they had the condition. Likewise, a recent qualitative study by Dearie and associates explored the knowledge and attitudes towards diabetes among i-Taukei Fijians living in Australia [32]. Participants generally demonstrated an understanding of the mechanisms involved in the development of T2DM, but others were unable to define the condition or believed there was a general lack of knowledge around diabetes in their community [32]. A retrospective audit of the Tongan National Diabetes Registry reported that only around 3% of individuals living with diabetes during the period 2011 to 2012 accessed health care indicating that many Tongans failed to utilise relevant services [9].
It has been well established that diabetes complications can be reduced by implementing positive lifestyle changes [31, 32, 33, 34, 35, 36]. Participants in this study spoke about their fear of limb amputation and it was recognised that poor glycaemic control may lead to this outcome [37]. Preventing foot ulcers is an important strategy for avoiding amputation. Complication awareness should be a key area of focus in any lifestyle-intervention that aims to promote optimal glycaemic control in people living with T2DM. The Tongan Ministry of Health’s NCD Strategy 2015–2020 has four key areas of action including alcohol reduction, good nutrition, healthy environments, and tobacco control. Interventions, which focus on one or more of these areas, are carried out in schools, churches, and various workplaces with the aim to reduce NCDs morbidity and mortality [38]. However, despite this strategy there are minimal resources available to support this work.
The Ministry of Health has collaborated with The Ministry of Education, the Tonga Health Promotion Foundation, World Health Organization, and the University of Otago to develop a School Food Policy- A Pathway to a Healthier Life [38]. This food policy came into force in 2007 and was updated in 2012 and launched on the 12th of November 2019 [38]. The policy aims to ensure that healthy and nutritious food are readily available to students both at home and sold on school compound [38]. This policy incorporates into the rules and regulations of all schools in Tonga permitting only the foods outlined in the policy for children to bring to school. This also allowed schools to negotiate with shop owner’s affordability of foods sold to students by developing good habits and increasing knowledge regarding what a healthy diet consists of in early life prevention of T2DM may become more of a reality [38].
Food is of cultural importance in Tonga posing a challenge for healthcare interventions. Some participants in this study acknowledged that a barrier to maintaining optimal BGL’s was their propensity for high fat, sugary foods, and limited ability to purchase healthy options (due to either cost or availability). A 1998 study aimed to identify and quantify barriers to diabetes care from a multiethnic, urban community perspective (mainly New Zealand Europeans, Maori, and Pacific Islanders). Barriers to care were quantified among 1862 (2.1 %) individuals living with diabetes out of a total surveyed population of 90 477. In spite of major cultural differences between participants, the top 10 barriers were similar between the ethnic groups [39]. The most important barriers perceived included that benefits of self-care were outweighed by the disadvantages (20 % Europeans, 20 % Maori, 29 % Pacific Islanders, 16 % others, p = 0.001), lack of community-based services (13 % Europeans, 27 % Maori, 25 % Pacific Islanders, 11 % others, p = 0.001) and the limited range of services were available (15 % Europeans, 22 % Maori, 20 % Pacific Islanders, 14 % others, p = 0.05) [39]. The authors reported that systematic action to reduce impact of these barriers, in both patients and populations, could result in an improvement in diabetes outcomes [39].
Foods considered too fatty for consumption by “Western” standards, such as lamb flaps, are enjoyed in Tonga as delicacies, and eating large portions of food is considered polite, especially in the context of social gatherings [7]. A recent review by Underhill and Singh-Peterson reported that purchasing fresh fruit and vegetables in Tonga can be a highly capricious venture [40]. For much of the year, commercial fruit and vegetable supply-chains are restricted to a few retail outlets selling limited quantities of both local and imported produce. Similarly, Morgan and associates conducted focus group discussions with both indigenous and Indian Fijians residing in Suva to investigate factors influencing fruit and vegetable intake. They found that increasing preferences for processed and imported foods, and inconsistent availability and affordability of high-quality, low-priced, fresh produce, were barriers to fruit and vegetable consumption [27]. Promoting dietary habits based on increased consumption of fresh fruit and vegetables should be a critical first step in tackling NCD’s.
Nevertheless, healthy food accessibility is an issue in Tonga. Corner shops have cheaper alternatives to bottled water and minimally processed food items such as sugary drinks and products high in fat and simple carbohydrates are abundantly available. In Tonga there are small corner shops in every village where Tongans buy their weekly groceries. Policies need to focus on increasing the availability of affordable, nutritious products and decreasing the number of cheap, highly processed food imports [19].
Evidence for the positive influence of ‘family’ on an individual’s glycaemic control has been accruing [41, 42, 43]. In the USA, McElfish and colleagues’ pilot-tested a home-based model of diabetes education with Marshallese individuals and their extended family members [44]. More than three-fourths (78%) of participants were retained in the study and a 7% reduction in HbA1c was observed among those with T2DM. The authors concluded that culturally targeted diabetes interventions, which embrace family members, may lead to better results for individuals with T2DM than traditional self-management education programs [44]. Similarly, a recent study from the USA illustrates how leveraging spiritual beliefs in an African American church based diabetes intervention may promote positive behaviour change [45]. Pacific Island churches play a significant role in the culture and authoritative systems of the communities that they serve, as well as providing a place for fellowship and communication. A recent prospective, pre-post study of a church-wide diabetes education and support programme was carried out with a group of Samoans living in Sydney, Australia (46). Overall, 68/107(63.5%) of participants completed before and after intervention measures (mean age 48.9 ± 14.2 years; 57.2% female) [46]. The primary outcome, HbA1c, dropped significantly between baseline and follow-up among participants with known diabetes (8.1 ± 2.4% (65 mmol/mol) vs 7.4 ± 1.8% (57 mmol/mol); p = 0.040) [46]. Church-based programs may be more realistic when aiming for adherence to healthier lifestyle behaviours as this approach has been shown to be effective in improving diabetes complications as well as diabetes management in Pacific Island populations elsewhere [47, 48, 49, 50].
Understanding Tongans perceptions of the role of both western clinicians and local traditional healer’s practice is necessary as efficacy is clearly interwoven with culture, faith and politics [48]. Lifestyle-related interventions that include the church and family members plus the input of local healers may contribute to not only a greater understanding of why Tongans choose to follow certain treatment pathways but ultimately lead to better physical and psycho-social outcomes for people living with T2DM.