This study included 105 participants who are being treated for DM2 in outpatient clinics of Palestinian Ministry of Health. Our study group had mainly adequate control of HbA1C and TG. This study group showed that obese patients who used metformin were in better control of DM2 than other groups who used insulin, although use of insulin was not very common. Consumption of fish and nuts although showed protective effect in Patients with DM2 but this relationship was fluctuating with groups in the highest category of fish consumption having higher plasma glucose and HbA1C. The only factor that was associated with TG is body fat, TG was low and use of atorvastatin is common.
The Palestinian society is continuously changing because there is a shift from traditional Mediterranean diet to westernized foods and readily prepared food. The classical risk factors for CVD are increasing including smoking, obesity, dyslipidemia and type 2 diabetes mellitus (DM2) (13). DM2 happens at rate of 10% in Palestinian Occupied territories and its risk factors include: age, positive family history, high TG level and high waist to hip ratio (14). The American Diabetes Association estimates that the yearly cost of treating a person with DM2 is 5 times more than a person without DM2 (13, 243 USD versus USD 2,560). Blindness, leg amputation and people with DM2 may die from CVD. Cost for DM2 comes from medications such as insulin and oral hypoglycemic, hospitalization, consultation and treatment for complications(15). In our study group, fat mass correlated significantly with plasma glucose, and adults who are obese have higher HbA1C than adults who are less obese. Sex, education, working status and smoking were not significantly related to measures of glyceamia.
Majority of our study group used metformin to control DM2. Fewer number of participants used combination of insulin and metformin and insulin alone. HbA1C was the lowest among the group who used metformin. At the same time, the group that used metformin were more obese. Metformin which is dimethylbiguanide has become first line therapy for oral glucose lowering agent to manage DM2 (16). The primary role of metformin in prevention of DM2 is through suppression of hepatic glucose production. Also, metformin may interfere with energy metabolism through activation of AMP-activated protein kinase and also through inhibition of gluconeogenesis (17). The benefits of metformin for human health is beyond its effect on lowering glucose levels. Metformin is associated with weight loss in cohort studies and the mechanisms involved include reduction in hepatic gluconeogenesis and reduction in insulin production. Other evidence indicate that metformin reduces weight due to modifying appetite regulatory centers, altering gut microbiome(18). Use of metformin is more common among obese participants. In our study, users of insulin were fewer than users of metformin. Worldwide, the number of persons who used insulin in 2018, 405.6 million (95% CI 315·3 million–533·7 million) and this number is projected to increase by 100 million by 2030. The ultimate goal of use of insulin is to reduce disability related lost years, however use of newer oral anti-hyperglycemic drugs and aiming for higher HbA1C, the use DALYs that will be averted will increase (19).
In our study frequent consumption of fish is associated with fluctuations in plasma glucose levels, with people with more modest consumption of fish are more likely to have better glycemia control values. Fish consumption is associated with reduced levels of inflammatory markers.The anti-inflammatory related to consumption of fish is associated with reduced production pro-inflammatory eicosanoids derived from arachidonic acid and increased conversion of Eicosapentanoic acid ( EPA) and decosahexanoic acid ( DHA) to anti-inflammatory to eicosanoids (e.g PGE3, TXA3, LTA5), resolvins and protectins. Other components include Se, taurine and proteins(20). We showed previously in studies from Inuit people of Canada, that consumption of fish is associated with increase in blood glucose (21). The consumption of fish is associated with increase in metals and organic pollutants (POPs) which is associated with increased risk of DM2 which could lead to reduced insulin secretion(22). One study on fish collected from Mediterranean Sea indicated that fish is associated with contamination. Author was unable to find studies that link fish consumption to other socioeconomic and life-style factors.
Nuts and tree nuts are botanically defined as dry fruits with a single seed and an ovary wall which becomes hard at maturation. In Palestine, among edible nuts in Palestine are; almonds, cashews, macademia and walnuts, peanuts. Consumption of 5 servings of nuts per week was inversely associated with lowering DM2 in Nurses' Health Study, but other studies did not show significant relationships (23). Our study indicates that HbA1C is reduced by nuts intake, but plasma glucose was not reduced by nuts intake. There was no consistent association between nuts intake and obesity. According to author knowledge, most Palestinian people consume salted nuts, but how intake of salt in this case affect CVD needs further studies.
Our data indicate that there is no association between TG and plasma glucose and HbA1C. Increase in plasma triglyceride (TG) is a leading cause of cardiovascular disease in patients with diabetes mellitus (DM2). In human plasma triglycerides are always carried by lipoproteins such as VLDL and LDL, insulin regulates VLDL concentrations through lipoprotein lipase. Hyperglycemia is not always associated with increase in plasma TG but insulin, so when there is insulin resistance associated with increase in insulin the level of plasma TG will increase(24). 84% of the study group used Atorvastatin which represents the most suitable method to lower the risk of CVD in patients with DM2(25). Having high TG is common among patients who use statins to control the cholesterol which is associated with more common CVD related to increase in TG. The level of TG is low in this group indicating that the level of insulin resistance did not induce hypertriglyceridemia, but other data is needed to analyze CVD risk in this study group(26).