Essential trace elements of potential importance in nutritional management of diabetes mellitus

Comparative evaluation for phytochemical composition and regulation of blood glucose, hepatic oxidative stress and insulin resistance in mice and HepG2 models of four typical Chinese dark teas

BACKGROUND

Dark tea, comprising one of the six major teas, has many biological activities, which originate from their active substrates, such as polyphenols, polysaccharides, and so on. The hypoglycemic effect is one of its most prominent activities, although less is known about their evaluation and potential role in the hypoglycemic mechanism.

RESULTS

In the present study, we separately analyzed the phytochemical composition, glycosidase inhibition and free radical scavenging activities, and hypoglycemic activity in type 2 diabetes mellitus mice, as well as the alleviation of insulin resistance in HepG2 cells of four dark tea aqueous extracts. The results showed that the phytochemical composition of dark tea aqueous extracts was significantly different, and they all had good glycosidase inhibition and free radical scavenging activities, in vivo hypoglycemic activity and alleviation of insulin resistance, and could also activate the phosphatidylinositol 3-kinase-Akt-perixisome proliferation-activated receptor cascade signaling pathway to regulate glucose and lipid metabolism, change the key enzyme activities related to glucose metabolism and antioxidant activity, and reduce oxidative stress and inflammatory factor levels. Among them, Liubao brick tea (LBT) and Pu-erh tea (PET) possessed better glycosidase inhibitory activity, in vivo hypoglycemic activity and improved insulin resistance activity, whereas Qingzhuan brick tea and Fuzhuan brick tea had better free radical scavenging activity, which may be explained by their distinct phytochemical compositions, such as tea proteins, polysaccharides, polyphenols, catechins, and tea pigments and some elements.

CONCLUSION

Dark tea is a highly attractive candidate for developing antidiabetic food, LBT and PET may be good natural sources of agricultural products with anti-diabetic effects. © 2021 Society of Chemical Industry.

Reduced serum concentrations of vitamin B12 and folate and elevated thyroid-stimulating hormone and homocysteine levels in first-trimester pregnant Saudi women with high A1C concentrations

Better understanding of the risk factors for diabetes can lead to proper prevention of this devastating metabolic abnormality. It is hypothesized that diabetes pathogenesis is linked to complex metabolic abnormalities involving homocysteine (HCY) pathways and affecting B₁₂, folate, and thyroid-stimulating hormone (TSH) concentrations. This study was conducted to determine the associations between serum concentrations of vitamin B₁₂, folate, TSH, and HCY in pregnant women with normal glycemic control, diabetes, or prediabetes. This cross-sectional study included 1159 healthy first-trimester pregnant women who were randomly selected from antenatal clinics in 2 hospitals and 21 health care centers across Al-Madinah, Saudi Arabia. Data collected included clinical history and blood sample analyses for serum folate, vitamin B₁₂, TSH, HCY, and glycated hemoglobin (A1C). Participants were classified with normal A1C (<5.7%), prediabetes (≥5.7 and <6.5%), or undiagnosed type 2 diabetes (≥6.5%). Results revealed that 79.5% of the participants had normal A1C levels, whereas 19.3% and 1.21% had A1C levels in prediabetic and diabetic ranges, respectively. Serum concentrations of vitamin B₁₂ and folate were lower in prediabetes subjects than in participants with normal A1C concentrations, whereas serum concentrations of TSH and HCY were significantly higher. There was a strong negative correlation among the concentrations of A1C, vitamin B_12, and folate, whereas positive correlations among A1C, TSH, and HCY were reported. Regression analysis identified TSH as having the strongest impact on A1C concentrations. These complex metabolic changes that occur at the prediabetic stage that involve TSH, HCY, folate, and vitamin B₁₂ might direct research on diabetes prevention.

Effect of Trace and Toxic Elements of Different Brands of Cigarettes on the Essential Elemental Status of Irish Referent and Diabetic Mellitus Consumers

Cigarette smoking interferes with the metal homeostasis of the human body, which plays a crucial role for maintaining the health. A significant flux of heavy metals, among other toxins, reaches the lungs through smoking. In the present study, the relationship between toxic element (TE) exposure via cigarette smoking and diabetic mellitus incidence in population living in Dublin, Ireland is investigated. The trace [zinc (Zn) and selenium (Se)] and toxic elements arsenic (As), aluminum (Al), cadmium (Cd), nickel (Ni), mercury (Hg), and lead (Pb) were determined in biological (scalp hair and blood) samples of patients diagnosed with diabetic mellitus, who are smokers living in Dublin, Ireland. These results were compared with age- and sex-matched healthy, nonsmokers controls. The different brands of cigarette (filler tobacco, filter, and ash) consumed by the studied population were also analyzed for As, Al, Cd, Ni, Hg, and Pb. The concentrations of TEs in biological samples and different components of cigarette were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials (CRM). The recovery of all the studied elements was found to be in the range of 96.4-99.7% in certified reference materials. The filler tobacco of different branded cigarettes contains Hg, As, Al, Cd, Ni, and Pb concentrations in the ranges of 9.55-12.4 ng/cigarette, 0.432-0.727 μg/cigarette, 360-496 μg/cigarette, 1.70-2.12 μg/cigarette, 0.715-1.52 μg/cigarette, and 0.378-1.16 μg/cigarette, respectively. The results of this study showed that the mean values of Al, As, Cd, Hg, Ni, and Pb were significantly higher in scalp hair and blood samples of diabetic mellitus patients in relation to healthy controls, while the difference was significant in the case of smoker patients (p < 0.001). The levels of all six toxic elements were twofolds to threefolds higher in scalp hair and blood samples of nondiabetic mellitus smoker subjects as compared to nonsmoker controls. The high exposure of toxic metals as a result of cigarette smoking may be synergistic with risk factors associated with diabetic mellitus.

Micronutrient status in type 2 diabetes: a review

Type 2 diabetes is characterized by significant losses of important micronutrients due to metabolic basis of the disease and its complications. Evidence of changes in trace mineral and vitamin metabolism as a consequence of type 2 diabetes is reviewed in this chapter. This review is not a meta-analysis but an overview of the micronutrient status, metabolic needs, and potential micronutrient requirements in type 2 diabetics. This chapter will not concentrate on vitamin D and type 2 diabetes as this is a topic that has been extensively reviewed before. The less well-known micronutrients notably zinc, magnesium, chromium, copper, manganese, iron, selenium, vanadium, B-group vitamins, and certain antioxidants are assessed. While some evidence is available to demonstrate the positive influence of micronutrient supplementation on glycemic control, much remains to be investigated. Additional research is necessary to characterize better biomarkers of micronutrient status and requirements in type 2 diabetics. The optimal level of micronutrient supplementation to achieve glucose homeostasis in type 2 diabetics remains a challenge.

Comparative metal distribution in scalp hair of Pakistani and Irish referents and diabetes mellitus patients

BACKGROUND

The essential metals, chromium (Cr), magnesium (Mg), manganese (Mn) and zinc (Zn), are necessary for many metabolic processes and their homeostasis is crucial for life. The toxic metals, cadmium (Cd) and lead (Pb), have no beneficial role in human metabolism. The aim of this study was to investigate the levels of Cd, Cr, Mg, Mn, Pb, and Zn in scalp hair samples of type 2 diabetes mellitus patients of both genders, ages ranging from 30 to 50 y, and belong to urban areas of Ireland and Pakistan. For comparison purposes, age matched non-diabetic subjects of both countries were selected as referents.

METHODS

The concentrations of metals in scalp hair samples were measured by inductively coupled plasma atomic emission spectrophotometer and atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by conventional wet-acid-digestion method and using certified reference materials.

RESULTS

The mean values of Cd and Pb were significantly higher in scalp hair samples of both Pakistani and Irish diabetic patients as compared to referents of both countries (P<0.001). In contrast, lower Cr, Mg, Mn, and Zn (P<0.01) concentrations were detected in scalp hair derived from patients with type 2 diabetes versus healthy subjects of both countries.

CONCLUSION

This study showed that, increased toxic elements and decreased essential elements are associated with diabetes mellitus. Therefore, these elements may play a role in the development and pathogenesis of diabetes mellitus.

Potassium, calcium, magnesium, and sodium levels in biological samples of hypertensive and nonhypertensive diabetes mellitus patients

There is accumulating evidence that the metabolism of several essential elements is altered in diabetes mellitus and that these nutrients might have specific roles in the pathogenesis and progress of this disease. The aim of the present study was to compare the level of essential elements, potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na), in biological samples (whole blood, urine, and scalp hair) of patients who have hypertensive diabetes mellitus type 2 (n = 254) and nonhypertensive diabetes mellitus type 2 (n = 228) with those of nondiabetic as control subjects (n = 182; age range of both genders 45-75). The element concentrations were measured by means of an atomic absorption spectrophotometer after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet acid digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of 99.1-99.9% of certified values. The results of this study showed that the mean values of K, Mg, and Ca were significantly reduced, while Na level were higher in blood and scalp hair samples of hypertensive diabetic (HD) patients and nonhypertensive diabetic (NHD) patients as compared to control subjects of both genders (p < 0.05), but level of K in the biological samples of nonhypertensive diabetic patient was found to be higher, but it was not significant (p = 0.05).The urinary levels of these elements were found to be higher in both HD and NHD patients than in the age-matched healthy controls. These results are consistent with those obtained in other studies, confirming that deficiency and efficiency of some essential trace metals may play a role in the development of diabetes mellitus.

Copper, chromium, manganese, iron, nickel, and zinc levels in biological samples of diabetes mellitus patients

There is accumulating evidence that the metabolism of several trace elements is altered in diabetes mellitus and that these nutrients might have specific roles in the pathogenesis and progress of this disease. The aim of present study was to compare the level of essential trace elements, chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn) in biological samples (whole blood, urine, and scalp hair) of patients who have diabetes mellitus type 2 (n = 257), with those of nondiabetic control subjects (n = 166), age ranged (45-75) of both genders. The element concentrations were measured by means of an atomic absorption spectrophotometer after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet-acid-digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of (97.60-99.49%) of certified values. The results of this study showed that the mean values of Zn, Mn, and Cr were significantly reduced in blood and scalp-hair samples of diabetic patients as compared to control subjects of both genders (p < 0.001). The urinary levels of these elements were found to be higher in the diabetic patients than in the age-matched healthy controls. In contrast, high mean values of Cu and Fe were detected in scalp hair and blood from patients versus the nondiabetic subjects, but the differences found in blood samples was not significant (p < 0.05). These results are consistent with those obtained in other studies, confirming that deficiency and efficiency of some essential trace metals may play a role in the development of diabetes mellitus.

Action mechanism of metallo-allixin complexes as antidiabetic agents

The metabolic syndrome is a group of factors associated with an increased risk of atherosclerosis and diabetes. Diabetes mellitus (DM) is classified into 2 major types - type 1 DM and type 2 DM - characterized by chronic hyperglycemia resulting from defects in insulin secretion and insulin action, respectively. Several synthetic pharmaceuticals have been developed and clinically used for treating DM; however, these pharmaceuticals continue to cause side effects. Recently, we proposed that oxovanadium(IV) (vanadyl) and zinc(II) (zinc) complexes are potent antidiabetic agents for both type 1 and type 2 DM therapy. This article reviews the vanadyl- and zinc-allixin and their related complexes that are being currently developed as novel types of antidiabetic metal complexes, focusing on their action mechanism in terms of regulation of the insulin signaling pathway and inhibition of lipolysis signaling in adipocyte cells.

Nutritional therapy for diabetes mellitus

Dietary therapy affects diabetes management in the dog and cat directly through control of blood glucose and indirectly through control of obesity and lipid abnormalities. Caloric intake, the feeding schedule, food form, macronutrient composition of the diet, and the presence of any concurrent problems must all be considered when planning the dietary regime. Generally, the healthy diabetic dog or cat should be fed a diet with increased fiber and moderate carbohydrate in a quantity sufficient to attain and maintain optimal body weight; whenever possible, the daily food allotment should be divided into multiple small meals that are fed through the day and evening when the physiologic effects of administered insulin are present. Once established, the dietary regime should be kept constant from day to day. Following these guidelines will help minimize postprandial hyperglycemia and may lead to a decreased exogenous insulin requirement. However, if a concurrent disorder has dietary requirements that conflict with those for the diabetic pet, nutritional management of the other disorder should usually take precedence.