CA : A Cancer Journal for Clinicians

Intensive insulin therapy prevents the progression of diabetic microvascular complications in Japanese patients with non-insulin-dependent diabetes mellitus: a randomized prospective 6-year study.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(12)60283-9.pdf

Prediabetes: a high-risk state for diabetes development

Context With increasing globalization and East-West exchanges, the increasing epidemic of type 2 diabetes in Asia has far-reaching public health and socioeconomic implications. Objective To review recent data in epidemiologic trends, risk factors, and complications of type 2 diabetes in Asia. Evidence Acquisition Search of MEDLINE using the term diabetes and other relevant keywords to identify meta-analyses, systematic reviews, large surveys, and cohort studies. Separate searches were performed for specific Asian countries. The review was limited to English-language articles published between January 1980 and March 2009; publications on type 1 diabetes were excluded. Evidence Synthesis The prevalence of diabetes in Asian populations has increased rapidly in recent decades. In 2007, more than 110 million individuals in Asia were living with diabetes, with a disproportionate burden among the young and middle aged. Similarly, rates of overweight and obesity are increasing sharply, driven by economic development, nutrition transition, and increasingly sedentary lifestyles. The “metabolically obese” phenotype (ie, normal body weight with increased abdominal adiposity) is common in Asian populations. The increased risk of gestational diabetes, combined with exposure to poor nutrition in utero and overnutrition in later life in some populations, may contribute to the increasing diabetes epidemic through “diabetes begetting diabetes” in Asia. While young age of onset and long disease duration place Asian patients with diabetes at high risk for cardiorenal complications, cancer is emerging as an important cause of morbidity and mortality. Conclusions Type 2 diabetes is an increasing epidemic in Asia, characterized by rapid rates of increase over short periods and onset at a relatively young age and low body mass index. Prevention and control of diabetes should be a top public health priority in Asian populations.

Diabetes in Asia: epidemiology, risk factors, and pathophysiology.

Tea is the most consumed drink in the world after water. Green tea is a 'non-fermented' tea, and contains more catechins, than black tea or oolong tea. Catechins are in vitro and in vivo strong antioxidants. In addition, its content of certain minerals and vitamins increases the antioxidant potential of this type of tea. Since ancient times, green tea has been considered by the traditional Chinese medicine as a healthful beverage. Recent human studies suggest that green tea may contribute to a reduction in the risk of cardiovascular disease and some forms of cancer, as well as to the promotion of oral health and other physiological functions such as anti-hypertensive effect, body weight control, antibacterial and antivirasic activity, solar ultraviolet protection, bone mineral density increase, anti-fibrotic properties, and neuroprotective power. Increasing interest in its health benefits has led to the inclusion of green tea in the group of beverages with functional properties. However, although all the evidence from research on green tea is very promising, future studies are necessary to fully understand its contributions to human health, and advise its regular consumption in Western diets, in which green tea consumption is nowadays limited and sporadic.

Beneficial Effects of Green Tea—A Review

Methods:We examined the effect of tea drinking, measured in detail for the past decades, on the risk of newly diagnosed hypertension in 1507 subjects (711 men and 796 women), 20 years or older, who did not have a hypertensive history during 1996 in Taiwan. Results:Sixhundredsubjects(39.8%)werehabitualtea drinkers,definedbyteaconsumptionof120mL/dormore foratleast1year.Comparedwithnonhabitualteadrinkers,theriskofdevelopinghypertensiondecreasedby46% for those who drank 120 to 599 mL/d and was further reduced by 65% for those who drank 600 mL/d or more after carefully adjusting for age, sex, socioeconomic status, family history of hypertension, body mass index, waist-hip ratio, lifestyle factors (total physical activity, highsodiumintake,cigarettesmoking,alcoholconsumption, and coffee drinking), and dietary factors (vegetable, fruit, unrefined grain, fish, milk, visible-fat food, and deep fried food intake). However, tea consumption for more than 1 year was not associated with a further reduction of hypertension risk. Conclusion: Habitual moderate strength green or oolong tea consumption, 120 mL/d or more for 1 year, significantly reduces the risk of developing hypertension in the Chinese population. Arch Intern Med. 2004;164:1534-1540

https://jamanetwork.com/journals/jamainternalmedicine/articlepdf/217219/ioi30296.pdf

The protective effect of habitual tea consumption on hypertension.

OBJECTIVES: To compare the different correlations of body mass index (BMI) and percent body fat (BF%) with other ethnic groups and to evaluate the appropriateness of Asia-Pacific redefining obesity criteria in the Taiwanese population The corresponding BF% to BMI cutoffs of overweight and obesity will also be studied DESIGN: A cross-sectional epidemiological survey SUBJECTS: A total of 509 male and 570 female Taiwanese subjects aged ≥20 y sampled by the systematic stratified clustering sampling method were analyzed MEASUREMENTS: BMI was obtained by body weight (kg) divided by squared body height (m2) The estimated BMI (BMIe) was deduced from the Caucasian-based four-compartment equation (4C) BF% measured by the methods of dual-energy X-ray absorptiometry (DXA) or Caucasian-based 4C were used and abbreviated as DXA-BF and 4C-BF, respectively RESULTS: The curvilinear relationship between age and BMI or DXA-BF was established When compared by age-stratified groups, Taiwanese subjects had a higher BF% (4C-BF) in any given BMI than Caucasians That is, the level of 4C-BF for BMI≥25 kg/m2 in Taiwanese subjects was similar to BMI≥30 kg/m2 in Caucasians The BMIe values of 25 and 30 kg/m2 were nearly equal to the BMIs of 236 and 253 kg/m2 in males, and 227 and 248 kg/m2 in females, respectively The 4C-BF of 25% was nearly equal to a BMI of 262 kg/m2 in males, and 35% was equal to a BMI of 244 kg/m2 in females Consequently, the DXA-BF cutoffs for BMIs of 23 and 25 kg/m2 were compatible to 23 and 25% in males, and 35 and 38% in females, respectively CONCLUSION: It was demonstrated that Taiwanese subjects had a relatively lower BMI but a higher BF% than Caucasians In general, the newly proposed Asia-Pacific BMI cutoffs for overweight (≥23 kg/m2) and obesity (≥25 kg/m2) may be acceptable to both male and female Taiwanese subjects The corresponding BF% (DXA-BF) cutoffs for obesity would be 25% in male and 38% in female Taiwanese subjects, respectively

Low body mass index but high percent body fat in Taiwanese subjects: implications of obesity cutoffs.

Objective: To disclose the possible relationship between habitual tea consumption and changes in total body fat and fat distribution in humans.

Research Methods and Procedures: A cross-sectional survey of 1210 epidemiologically sampled adults (569 men and 641 women) were enrolled in our study. Tea consumption and other lifestyle characteristics were obtained by structured questionnaires. Percent body fat (BF%) was measured using bioelectrical impedance analysis. Body fat distribution was assessed using waist-to-hip ratio (WHR).

Results: Among the 1103 analyzed subjects, 473 adults (42.9%) consumed tea once or more per week for at least 6 months. The habitual tea drinkers were male-dominant, more frequently current smokers, and alcohol or coffee drinkers than the nonhabitual tea drinkers. Habitual tea drinkers for more than 10 years showed a 19.6% reduction in BF% and a 2.1% reduction in WHR compared with nonhabitual tea drinkers. The multiple stepwise regression models revealed that men, older age, higher BMI, and current smokers were positive factors for BF% and WHR. In contrast, longer duration of habitual tea consumption and higher total physical activity were negative factors for BF%. Longer duration of habitual tea consumption, higher socioeconomic status, and premenopausal status were negative factors for WHR.

Discussion: An inverse relationship may exist among habitual tea consumption, BF%, and body fat distribution, especially for subjects who have maintained the habit of tea consumption for more than 10 years.

https://onlinelibrary.wiley.com/doi/pdf/10.1038/oby.2003.149

Relationship among habitual tea consumption, percent body fat, and body fat distribution

To better understand the insulin-independent plasma glucose-lowering action of metformin, we used streptozotocin (STZ)-induced diabetic rats to investigate the possible mechanisms. Oral intake of metformin decreased the plasma glucose of STZ-induced diabetic rats with a parallel increase of plasma beta-endorphin-like immunoreactivity (BER). Mediation of opioid mu-receptors in the action of metformin was identified by the blockade of receptors with antagonist in STZ-induced diabetic rats and the failure of action in opioid mu-receptor knockout diabetic mice. Release of BER from adrenal glands by metformin was characterized, using bilateral adrenalectomy and the release of BER from isolated adrenal medulla of STZ-induced diabetic rats. Repeated treatment with metformin in STZ-induced diabetic rats increased the mRNA and protein levels of GLUT-4 in soleus muscle that was blocked by naloxonazine. Reduction of the mRNA or protein levels of hepatic PEPCK was also impeded in the same group of STZ-induced diabetic rats. In conclusion, our results provide novel mechanisms for the plasma glucose-lowering action of metformin, via an increase of beta-endorphin secretion from adrenal glands to stimulate opioid mu-receptor linkage, leading to an increase of GLUT-4 gene expression and an attenuation of hepatic PEPCK gene expression in STZ-induced diabetic rats.

https://diabetes.diabetesjournals.org/content/diabetes/55/3/819.full.pdf

Novel mechanism for plasma glucose-lowering action of metformin in streptozotocin-induced diabetic rats.

Background: Researchers have hypothesized that bone mineral density (BMD) may be influenced by chemical compounds such as caffeine, phytoestrogen, fluoride, and many compounds that are contained in tea extracts. Hence, the relationship between habitual tea consumption and BMD is an interesting issue. Methods: Based on an epidemiological survey, we enrolled 497 men and 540 women, 30 years and older, in our study. All subjects were questioned about their habit of tea consumption and other lifestyle characteristics by means of a structured questionnaire. Dual-energy x-ray absorptiometry was used to measure the BMD of the total body, lumbar spine (L1-L4), hip neck, and Ward triangle regions. Results: Five hundred two subjects (48.4%) were habitual tea drinkers, with a mean duration of tea consumption of approximately 10 years. Compared with nonhabitual tea drinkers, subjects with habitual tea consumption of 6 to 10 years showed higher lumbar spine BMDs, and those with consumption of more than 10 years showed the highest BMDs of all measured regions. Under the multiple stepwise regression models, sex, age, body mass index, total physical activity, and habit of tea consumption were the major significant variables for the different BMD regions. Regarding the behavioral characteristics of tea consumption, the duration of tea consumption was the only independent determinant for the BMDs. Conclusion: Habitual tea consumption, especially for more than 10 years, has significant beneficial effects on BMD of the total body, lumbar spine, and hip regions in adults.

https://jamanetwork.com/journals/jamainternalmedicine/articlepdf/211409/ioi10300.pdf

Chih Jen Chang

Papers

The protective effect of habitual tea consumption on hypertension.

Low body mass index but high percent body fat in Taiwanese subjects: implications of obesity cutoffs.

Relationship among habitual tea consumption, percent body fat, and body fat distribution

Novel mechanism for plasma glucose-lowering action of metformin in streptozotocin-induced diabetic rats.

Epidemiological evidence of increased bone mineral density in habitual tea drinkers.