Ketone bodies: from enemy to friend and guardian angel.

During starvation, fasting, or a diet containing little digestible carbohydrates, the circulating insulin levels are decreased. This promotes lipolysis, and the breakdown of fat becomes the major source of energy. The hepatic energy metabolism is regulated so that under these circumstances, ketone bodies are generated from ß-oxidation of fatty acids and secreted as ancillary fuel, in addition to gluconeogenesis. Increased plasma levels of ketone bodies thus indicate a dietary shortage of carbohydrates. Ketone bodies not only serve as fuel but also promote resistance to oxidative and inflammatory stress, and there is a decrease in anabolic insulin-dependent energy expenditure. It has been suggested that the beneficial non-metabolic actions of ketone bodies on organ functions are mediated by them acting as a ligand to specific cellular targets. We propose here a major role of a different pathway initiated by the induction of oxidative stress in the mitochondria during increased ketolysis. Oxidative stress induced by ketone body metabolism is beneficial in the long term because it initiates an adaptive (hormetic) response characterized by the activation of the master regulators of cell-protective mechanism, nuclear factor erythroid 2-related factor 2 (Nrf2), sirtuins, and AMP-activated kinase. This results in resolving oxidative stress, by the upregulation of anti-oxidative and anti-inflammatory activities, improved mitochondrial function and growth, DNA repair, and autophagy. In the heart, the adaptive response to enhanced ketolysis improves resistance to damage after ischemic insults or to cardiotoxic actions of doxorubicin. Sodium-dependent glucose co-transporter 2 (SGLT2) inhibitors may also exert their cardioprotective action via increasing ketone body levels and ketolysis. We conclude that the increased synthesis and use of ketone bodies as ancillary fuel during periods of deficient food supply and low insulin levels causes oxidative stress in the mitochondria and that the latter initiates a protective (hormetic) response which allows cells to cope with increased oxidative stress and lower energy availability. KEYWORDS: Ketogenic diet, Ketone bodies, Beta hydroxybutyrate, Insulin, Obesity, Type 2 diabetes, Inflammation, Oxidative stress, Cardiovascular disease, SGLT2, Hormesis.

Insulin: too much of a good thing is bad.

BACKGROUND: Insulin shares a limited physiological concentration range with other endocrine hormones. Not only too low, but also too high systemic insulin levels are detrimental for body functions. MAIN BODY: The physiological function and clinical relevance of insulin are usually seen in association with its role in maintaining glucose homeostasis. However, insulin is an anabolic hormone which stimulates a large number of cellular responses. Not only too low, but also excess insulin concentrations are detrimental to the physiological balance. Although the glucoregulatory activity of insulin is mitigated during hyperinsulinemia by dampening the efficiency of insulin signaling ("insulin resistance"), this is not the case for most other hormonal actions of insulin, including the promotion of protein synthesis, de novo lipogenesis, and cell proliferation; the inhibition of lipolysis, of autophagy-dependent cellular turnover, and of nuclear factor E2-related factor-2 (Nrf2)-dependent antioxidative; and other defense mechanisms. Hence, there is no general insulin resistance but selective impairment of insulin signaling which causes less glucose uptake from the blood and reduced activation of endothelial NO synthase (eNOS). Because of the largely unrestricted insulin signaling, hyperinsulinemia increases the risk of obesity, type 2 diabetes, and cardiovascular disease and decreases health span and life expectancy. In epidemiological studies, high-dose insulin therapy is associated with an increased risk of cardiovascular disease. Randomized controlled trials of insulin treatment did not observe any effect on disease risk, but these trials only studied low insulin doses up to 40 IU/day. Proof for a causal link between elevated insulin levels and cardiovascular disease risk comes from Mendelian randomization studies comparing individuals with genetically controlled low or high insulin production. CONCLUSIONS: The detrimental actions of prolonged high insulin concentrations, seen also in cell culture, argue in favor of a lifestyle that limits circadian insulin levels. The health risks associated with hyperinsulinemia may have implications for treatment regimens used in type 2 diabetes.

Insulin translates unfavourable lifestyle into obesity.

Lifestyle factors conferring increased diabetes risk are associated with elevated basal insulin levels (hyperinsulinaemia). The latter predicts later obesity in children and adolescents.A causal role of hyperinsulinaemia for adipose tissue growth is probable because pharmacological reduction of insulin secretion lowers body weight in people who are obese. Genetic inactivation of insulin gene alleles in mice also lowers their systemic insulin levels and prevents or ameliorates high-fat diet-induced obesity. Hyperinsulinaemia causes weight gain because of a physiological property of insulin. Insulin levels that are on the high side of normal, or which are slightly elevated, are sufficient to suppress lipolysis and promote lipogenesis in adipocytes. The effect of insulin on glucose transport or hepatic glucose production requires six or two times higher hormone levels, respectively.It seems justified to suggest a lifestyle that avoids high insulin levels in order to limit anabolic fat tissue activity.

Cardiometabolic effects of two coffee blends differing in content for major constituents in overweight adults: a randomized controlled trial.

PURPOSE: The hypothesis was tested that coffee types differing in content of major constituents also differ with regard to cardiometabolic effects. METHODS: Overweight persons (n = 118) were randomized to consume a dark roast [rich in N-methylpyridinium (NMP)] or medium roast (rich in caffeoylquinic acids, trigonelline) coffee blend for 3 months, after a washout period of 4 weeks. Before and after the intervention period, body weight and 15 further general and biochemical parameters were determined. RESULTS: Participants consumed an average of 4-5 cups per day. Mean body weight, body mass index and waist circumference did not change during the coffee consumption phase in either of the study groups. Systolic blood pressure decreased in the dark roast coffee group only (p < 0.05). High-density lipoprotein cholesterol levels increased in the medium roast coffee group only, and triglyceride levels increased in the dark roast coffee group only. Glucoregulation and insulin levels were not affected, although there was a small increase of hemoglobin A1c values in both groups. An increase of adiponectin levels occurred in the medium roast coffee group only and was negatively associated with NMP concentrations. Differences did not remain statistically significant after correction for multiple testing. CONCLUSIONS: Medium and dark roast coffee blends exert small but possibly relevant different cardiometabolic effects. Further studies of health outcomes in relation to coffee constituents seem warranted.

Effects of a Carbohydrate Meal on Lipolysis.

BACKGROUND: Due to the increasing prevalence of obesity and type 2 diabetes, effective dietary recommendations are needed. Previously, we developed the low-insulin method: by avoiding insulinogenic, i.e., insulin-release-triggering foods, insulin secretion becomes reduced, lipolysis is stimulated, and energy production is shifted to ketosis with excess ketone bodies exhaled in the form of acetone. Now, we investigate how quickly stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm) is achieved, whether and for how long a carbohydrate meal inhibits ketosis, and whether the responses differ in healthy adults with different insulin levels. METHODS: An oral glucose tolerance test was conducted, and body composition and fasting insulin were determined at the beginning and end of the 14-day study. Participants (n = 10) followed a ketogenic diet and performed continuous glucose monitoring. Ketosis levels were determined by measuring breath acetone concentrations. On day 8, two white bread rolls with jam (72 g carbohydrates) were consumed for breakfast. RESULTS: After seven days, all participants achieved stable ketosis (defined as fasting breath acetone concentration ≥ 7.0 ppm), which dropped from 8.2 to 5.7 ppm (p = 0.0014) after the carbohydrate meal. It took five days to achieve stable ketosis again. The stratification of participants into tertiles according to their fasting insulin levels demonstrated that individuals with low fasting insulin levels achieved stable ketosis again after two days and those with medium insulin levels after five days, while those with high baseline values did not reach stable ketosis by the end of the study. CONCLUSIONS: By carbohydrate restriction, stable ketosis can be achieved within one week. However, a single carbohydrate meal inhibits ketosis for several days. This effect is pronounced in individuals with elevated fasting insulin levels.

Sfrp5 correlates with insulin resistance and oxidative stress.

BACKGROUND: Secreted frizzled-related protein 5 (Sfrp5) has been described as novel adipokine in mice with insulin-sensitising and anti-inflammatory properties similar to adiponectin. The aim of this study was to compare serum concentrations and determinants of Sfrp5, its pro-inflammatory antagonist wingless-type MMTV integration site family member (Wnt)5a and adiponectin in humans and their regulation by coffee. MATERIAL AND METHODS: Serum concentrations of Sfrp5, Wnt5a and adiponectin were measured in 47 individuals who participated in a coffee intervention study. Associations with demographic, metabolic and immunological variables and regulation of serum levels by different amounts of daily coffee intake were analysed. RESULTS: At baseline, fasting serum Sfrp5 levels ranged between 96 and 4056 ng/mL. Sfrp5 was directly correlated with a surrogate of insulin resistance (homeostasis model assessment of insulin resistance/HOMA-IR; r = 0·32, P < 0·05) and with the oxidative stress markers 8-isoprostane (r = 0·44, P < 0·01) and nitrotyrosine (r = 0·52, P < 0·001). Adiponectin showed inverse correlations with several indices of insulin resistance (e.g. HOMA-IR, Stumvoll index; all P < 0·05) and a direct correlation with the anti-atherogenic apolipoprotein A-I (r = 0·56, P < 0·001). Coffee did not affect serum concentrations of Sfrp5. Serum Wnt5a concentrations were below the detection limit (0·02 ng/mL) in 81% of the study participants. CONCLUSIONS: In contrast to obese mouse models, serum Sfrp5 was directly related to HOMA-IR and oxidative stress in humans, but not with apolipoproteins, and thus, associations differed from those found for circulating adiponectin. These differences between Sfrp5 and adiponectin might be explained by differences in the investigated species.

Autonomous exercise game use improves metabolic control and quality of life in type 2 diabetes patients - a randomized controlled trial.

BACKGROUND: Lifestyle intervention in type 2 diabetes mellitus (T2DM) is effective but needs a special local setting and is costly. Therefore, in a randomized-controlled trial we tested the hypothesis that the autonomous use of the interactive exercise game Wii Fit Plus over a period of 12 weeks improves metabolic control, with HbA1c reduction as the primary outcome, and weight loss, reduction of cardiometabolic risk factors, physical activity and quality of life (secondary outcomes) in T2DM patients. METHODS: Participants (n = 220) were randomized into an intervention and a control group. The intervention group was provided with a Wii console, a balance board and the exercise game Wii Fit Plus for 12 weeks. The control group remained under routine care and received the items 12 weeks later. At baseline and after 12 weeks (and for the control group additionally after 12 weeks of intervention) the participants' health parameters, medication, physical activity and validated questionnaires for quality of life (PAID, SF12, WHO-5, CES-D) were requested and compared in a complete case analysis using the Mann-Whitney test and the Wilcoxon signed rank test. RESULTS: 80% of participants completed the 12-week study. Patients in the intervention group significantly improved HbA1c (from 7.1 ± 1.3% to 6.8 ± 0.9%; -0.3 ± 1.1%; p = 0.0002) in comparison to the control group (from 6.8 ± 0.9% to 6.7 ± 0.7%; -0.1 ± 0.5%) and also significantly reduced fasting blood glucose (from 135.8 ± 38.9 mg/dl to 126.6 ± 36.6 mg/dl; p = 0.04), weight (from 97.6 ± 19.2 kg to 96.3 ± 18.7 kg; p < 0.001) and body mass index (from 34.1 ± 6.5 kg/m2 to 33.5 ± 6.5 kg/m2; p < 0.001). Daily physical activity increased significantly (p < 0.001). Diabetes-dependent impairment, mental health, subjective wellbeing and quality of life also improved significantly, and the number of patients with depression decreased. Similar improvements were seen in the control group after exercise game intervention. CONCLUSIONS: In this trial a low-threshold intervention with the interactive exercise game Wii Fit Plus was able to motivate T2DM patients to improve physical activity, glucometabolic control and quality of life. TRIAL REGISTRATION: ClinicalTrials.gov NCT01735643.

Insulin and aging - a disappointing relationship.

Experimental studies in animal models of aging such as nematodes, fruit flies or mice have observed that decreased levels of insulin or insulin signaling promotes longevity. In humans, hyperinsulinemia and concomitant insulin resistance are associated with an elevated risk of age-related diseases suggestive of a shortened healthspan. Age-related disorders include neurodegenerative diseases, hypertension, cardiovascular disease, and type 2 diabetes. High ambient insulin concentrations promote increased lipogenesis and fat storage, heightened protein synthesis and accumulation of non-functional polypeptides due to limited turnover capacity. Moreover, there is impaired autophagy activity, and less endothelial NO synthase activity. These changes are associated with mitochondrial dysfunction and oxidative stress. The cellular stress induced by anabolic activity of insulin initiates an adaptive response aiming at maintaining homeostasis, characterized by activation of the transcription factor Nrf2, of AMP activated kinase, and an unfolded protein response. This protective response is more potent in the long-lived human species than in short-lived models of aging research resulting in a stronger pro-aging impact of insulin in nematodes and fruit flies. In humans, resistance to insulin-induced cell stress decreases with age, because of an increase of insulin and insulin resistance levels but less Nrf2 activation. These detrimental changes might be contained by adopting a lifestyle that promotes low insulin/insulin resistance levels and enhances an adaptive response to cellular stress, as observed with dietary restriction or exercise.

Impact of a Low-Insulin-Stimulating Bread on Weight Development-A Real Life Randomised Controlled Trial.

The impact on body weight development is usually analysed by comparing different diet types. Our approach was to change only one component, namely bread, common to most diets. In a single-centre triple-blind randomised controlled trial the effects of two different breads on body weight were analyzed without further lifestyle modification. Overweight adult volunteers (n = 80) were randomised 1:1 to exchange previously consumed breads for either a rye bread from milled whole grain (control) or a medium-carbohydrate, low-insulin-stimulating bread (intervention). Pre-tests demonstrated that the two bread types strongly differed in the glucose and insulin response elicited, but had similar energy content, texture and taste. The primary endpoint was the estimated treatment difference (ETD) in change of body weight after 3 months of treatment. Whereas body weight remained unchanged in the control group (-0.1 ± 2.0 kg), significant weight reduction was observed in the intervention group (-1.8 ± 2.9 kg), with an ETD of -1.7 ± 0.2 kg (p = 0.007), that was more pronounced in participants ≥ 55 years (-2.6 ± 3.3 kg), paralleled by significant reductions in body mass index and hip circumference. Moreover, in the intervention group, the percentage of participants with significant weight loss (≥1 kg) was twice as high as in the control group (p < 0.001). No other statistically significant changes in clinical or lifestyle parameters were noted. Simply exchanging a common insulinogenic bread for a low-insulin-stimulating bread demonstrates potential to induce weight loss in overweight persons, especially those at older age.

[Diabetes and cardiovascular health literacy in childhood and adolescence - a 12-year follow-up]. / Diabetes- und kardiovaskuläre Gesundheitskompetenz im Kindes- und Jugendalter ­ ein 12-Jahres-Follow-up.

BACKGROUND: The incidence of diabetes mellitus and cardiovascular diseases is increasing worldwide and also in Germany. The aim of the study was to assess the health literacy regarding these diseases in childhood and adolescence. METHODS: Students of the 5th-12th grade (grammar school ("Gymnasium"), secondary school forms ("Realschule" and "Hauptschule")) were interviewed in 2007 (n = 4383) and 2019 (n = 572) about diabetes and secondary complications. In addition, questions about other cardiovascular risk factors were asked in 2019. RESULTS: Diabetes-related questions were answered correctly by 56 % in 2007 as well as 53 % in 2019. Among others, 70 % (2007) as well as 75 % (2019) of the students stated "ate too much sugar" as a cause for type 1 diabetes. Further, questions about major risk factors for heart attack and stroke were answered correctly by only 33 % (for diabetes) and 43 %-53 % (for smoking) of students.Across all questions, a positive association indicated between the rate of correct answers and the educational level of the school institution; however, the differences remained marginal at 5-19 % between Gymnasium and Hauptschule or Realschule at both survey time points. A difference between genders was indicated in 2007 (girls: 59 % vs. boys: 52 %) and 2019 (girls: 56 % vs. boys: 51 %). CONCLUSION: Changes in health literacy regarding diabetes and other cardiovascular risk factors among 5th-12th grade students over the past 12 years could not be observed. The assumed self-infliction of type 1 diabetes may be perceived as discrimination by those affected.

Effectiveness of the Telemedical Lifestyle Intervention Program TeLIPro for Improvement of HbA1c in Type 2 Diabetes: A Randomized-Controlled Trial in a Real-Life Setting.

The effectiveness of the multimodal Telemedical Lifestyle Intervention Program (TeLIPro) was proven in the advanced stages of type 2 diabetes mellitus (T2DM). Since its therapeutic potential focusing on telemedical coaching without using a formula diet is unknown, we evaluated improvements in HbA1c, HbA1c normalisation rate, cardiometabolic risk factors, quality-of-life, and eating behaviour in real life. In this randomized-controlled trial, AOK Rhineland/Hamburg insured T2DM patients (n = 1163) were randomized (1:1) into two parallel groups, and 817 received the allocated intervention. In addition to routine care, all participants got scales, step counters, and access to an online portal. The TeLIPro group additionally received equipment for self-monitoring of blood glucose and telemedical coaching. Data were collected at baseline, after 6 and 12 months of intervention as well as after a 6-month follow-up. The primary endpoint after 12 months was (i) the estimated treatment difference (ETD) in HbA1c change and (ii) the HbA1c normalisation rate in those with diabetes duration < 5 years. The TeLIPro group demonstrated significantly stronger improvements in HbA1c (ETD -0.4% (-0.5; -0.2); p < 0.001), body weight, body-mass-index, quality-of-life, and eating behaviour, especially in T2DM patients with diabetes duration ≥ 5 years (ETD -0.5% (-0.7; -0.3); p < 0.001). The HbA1c normalisation rate did not significantly differ between groups (25% vs. 18%). Continuous addition of TeLIPro to routine care is effective in improving HbA1c and health-related lifestyle in T2DM patients with longer diabetes duration in real life.

High-Protein, Low-Glycaemic Meal Replacement Improves Physical Health-Related Quality of Life in High-Risk Persons for Metabolic Syndrome-A Subanalysis of the Randomised-Controlled ACOORH Trial.

While obesity impairs health-related quality of life (HRQOL), lifestyle interventions targeting weight reduction have been effective in improving HRQOL. Therefore, we hypothesised that a meal replacement-based lifestyle intervention, which has been shown to successfully reduce weight, would also improve HRQOL more effectively than a lifestyle intervention alone. In the international, multicenter, randomised-controlled ACOORH-trial (Almased-Concept-against- Overweight-and-Obesity-and-Related-Health-Risk), overweight or obese participants with elevated risk for metabolic syndrome (n = 463) were randomised into two groups. Both groups received telemonitoring devices and nutritional advice. The intervention group additionally used a protein-rich, low-glycaemic meal replacement for 6 months. HRQOL was estimated at baseline, after 3 and 12 months, using the SF-36 questionnaire, and all datasets providing HRQOL data (n = 263) were included in this predefined subanalysis. Stronger improvements in the physical component summary (PCS) were observed in the intervention compared to the control group, peaking after 3 months (estimated treatment difference 2.7 [1.2; 4.2]; p < 0.0001), but also in the long-term. Multiple regression analysis demonstrated that insulin levels and the achieved weight loss were associated with the mental component summary (MCS) after 12 months (p < 0.05). Thus, meal replacement-based lifestyle intervention is not only effective in weight reduction but, concomitantly, in enhancing HRQOL.

Early and Strong Leptin Reduction Is Predictive for Long-Term Weight Loss during High-Protein, Low-Glycaemic Meal Replacement-A Subanalysis of the Randomised-Controlled ACOORH Trial.

Lifestyle interventions including meal replacement are suitable for prevention and treatment of obesity and type-2-diabetes. Since leptin is involved in weight regulation, we hypothesised that a meal replacement-based lifestyle intervention would reduce leptin levels more effectively than lifestyle intervention alone. In the international, multicentre, randomised-controlled ACOORH-trial (Almased-Concept-against-Overweight-and-Obesity-and-Related- Health-Risk), overweight or obese participants with metabolic syndrome criteria (n = 463) were randomised into two groups and received telemonitoring devices and nutritional advice. The intervention group additionally used a protein-rich, low-glycaemic meal replacement. Data were collected at baseline, after 1, 3, 6, and 12 months. All datasets providing leptin data (n = 427) were included in this predefined subanalysis. Serum leptin levels significantly correlated with sex, body mass index, weight, and fat mass at baseline (p < 0.0001). Stronger leptin reduction has been observed in the intervention compared to the control group with the lowest levels after 1 month of intervention (estimated treatment difference −3.4 µg/L [1.4; 5.4] for females; −2.2 µg/L [1.2; 3.3] for males; p < 0.001 each) and was predictive for stronger reduction of body weight and fat mass (p < 0.001 each) over 12 months. Strongest weight loss was observed after 6 months (−5.9 ± 5.1 kg in females of the intervention group vs. −2.9 ± 4.9 kg in the control group (p < 0.0001); −6.8 ± 5.3 kg vs. −4.1 ± 4.4 kg (p = 0.003) in males) and in those participants with combined leptin and insulin decrease. A meal replacement-based lifestyle intervention effectively reduces leptin which is predictive for long-term weight loss.

A High-Protein and Low-Glycemic Formula Diet Improves Blood Pressure and Other Hemodynamic Parameters in High-Risk Individuals.

Low-caloric formula diets can improve hemodynamic parameters of patients with type 2 diabetes. We, therefore, hypothesized that persons with overweight or obesity can benefit from a high-protein, low-glycemic but moderate-caloric formula diet. This post-hoc analysis of the Almased Concept against Overweight and Obesity and Related Health Risk- (ACOORH) trial investigated the impact of a lifestyle intervention combined with a formula diet (INT, n = 308) compared to a control group with lifestyle intervention alone (CON, n = 155) on hemodynamic parameters (systolic and diastolic blood pressure (SBP, DBP), resting heart rate (HR), and pulse wave velocity (PWV)) in high-risk individuals with prehypertension or hypertension. INT replaced meals during the first 6 months (1 week: 3 meals/day; 2−4 weeks: 2 meals/day; 5−26 weeks: 1 meal/day). Study duration was 12 months. From the starting cohort, 304 (68.3%, INT: n = 216; CON: n = 101) participants had a complete dataset. Compared to CON, INT significantly reduced more SBP (−7.3 mmHg 95% CI [−9.2; −5.3] vs. −3.3 mmHg [−5.9; −0.8], p < 0.049) and DBP (−3.7 mmHg [−4.9; −2.5] vs. −1.4 mmHg [−3.1; 0.2], p < 0.028) after 12 months. Compared to CON, INT showed a pronounced reduction in resting HR and PWV after 6 months but both lost significance after 12 months. Changes in SBP, DBP, and PWV were significantly associated positively with changes in body weight and fat mass (all p < 0.05) and resting HR correlated positively with fasting insulin (p < 0.001) after 12 months. Combining a lifestyle intervention with a high-protein and low-glycemic formula diet improves hemodynamic parameters to a greater extent than lifestyle intervention alone in high-risk individuals with overweight and obesity.

A progressive increase in cardiovascular risk assessed by coronary angiography in non-diabetic patients at sub-diabetic glucose levels.

OBJECTIVE: Diabetes mellitus type 2 (DM2) is a risk factor for coronary heart disease (CHD). While there is a clear correlation of fasting blood glucose (FBG) and 2 h post-challenge blood glucose values (2h-BG) with microvascular complications, the risk for CHD conferred by glucose dysregulation antecedent to DM2 is less clear. Therefore, we investigated associations of FBG and 2h-BG values with the prevalence of CHD assessed by coronary angiography as the most sensitive diagnostic tool. RESEARCH DESIGN AND METHODS: Coronary angiography was performed in 1394 patients without known DM. Capillary blood glucose was analyzed before and 2 h after an oral glucose tolerance test. Associations between FBG as well as 2h-BG levels and the risk for CHD were assessed by logistic regression analysis. RESULTS: 1064 (75%) of patients were diagnosed with CHD. 204 (15%) were diagnosed with so far unknown DM2, 274 (20%) with isolated impaired fasting glucose (IFG), 188 (13%) with isolated impaired glucose tolerance (IGT) and 282 (20%) with both, IGT and IFG. We found a continuous increase in the risk for CHD with fasting and post-challenge blood glucose values even in the subdiabetic range. This correlation did however not suggest clear cut-off values. The increase in risk for CHD reached statistical significance at FBG levels of > 120 mg/dl (Odds Ratio of 2.7 [1.3-5.6] and 2h-BG levels > 140 mg/dl (141-160 mg/dl OR 1.8 [1.1-2.9], which was however lost after adjusting for age, sex and BMI. CONCLUSIONS: In our study population we found a continuous increased risk for CHD at fasting and 2h-BG levels in the sub-diabetic glucose range, but no clear cut-off values for cardiovascular risk.

Coffee and Lower Risk of Type 2 Diabetes: Arguments for a Causal Relationship.

Prospective epidemiological studies concur in an association between habitual coffee consumption and a lower risk of type 2 diabetes. Several aspects of these studies support a cause-effect relationship. There is a dependency on daily coffee dose. Study outcomes are similar in different regions of the world, show no differences between sexes, between obese versus lean, young versus old, smokers versus nonsmokers, regardless of the number of confounders adjusted for. Randomized controlled intervention trials did not find a consistent impact of drinking coffee on acute metabolic control, except for effects of caffeine. Therefore, lowering of diabetes risk by coffee consumption does not involve an acute effect on the post-meal course of blood glucose, insulin or insulin resistance. Several studies in animals and humans find that the ingestion of coffee phytochemicals induces an adaptive cellular response characterized by upregulation and de novo synthesis of enzymes involved in cell defense and repair. A key regulator is the nuclear factor erythroid 2-related factor 2 (Nrf2) in association with the aryl hydrocarbon receptor, AMP-activated kinase and sirtuins. One major site of coffee actions appears to be the liver, causing improved fat oxidation and lower risk of steatosis. Another major effect of coffee intake is preservation of functional beta cell mass via enhanced mitochondrial function, lower endoplasmic reticulum stress and prevention or clearance of aggregates of misfolded proinsulin or amylin. Long-term preservation of proper liver and beta cell function may account for the association of habitual coffee drinking with a lower risk of type 2 diabetes, rather than acute improvement of metabolic control.

The Epidemiological Boehringer Ingelheim Employee Study (Part 3): Association of Elevated Fasting Insulin Levels but Not HOMA-IR With Increased Intima Media Thickness and Arteriosclerosis in Middle-Aged Persons.

Background: Recently published genetic studies have indicated a causal link between elevated insulin levels and cardiovascular disease (CVD) risk. We, therefore, hypothesized that increased fasting insulin levels are also associated with precursors of CVD such as endothelial lesions. Methods: Middle-aged (≥40 years, n = 1,639) employees were followed up for the occurrence of increased intima media thickness (IMT ≥ 1 mm) or plaques in abdominal or cervical arteries (arteriosclerosis). Multivariable logistic regression analyses determined the incidence of increased IMT or arteriosclerosis. Adjusted relative risk (ARR) for increased IMT and arteriosclerosis was calculated by using Mantel-Haenszel analysis. Results: Increased IMT was diagnosed in 238 participants (15 %) and 328 (20 %) developed arteriosclerosis after 5 years of follow-up. Logistic regression analysis identified fasting insulin, BMI and smoking as risk factors for both cardiovascular endpoints (all p < 0.05), whereas age and diastolic blood pressure were risk factors for increased IMT only, and male sex was associated with incident arteriosclerosis only (all p < 0.01). Additional adjustment for BMI change during follow-up did not modify these associations (including fasting insulin), but adjustment for fasting insulin change during follow-up removed BMI as risk factor for both cardiovascular endpoints. Fasting insulin change during follow-up but not BMI change associated with increased IMT and arteriosclerosis (both p < 0.001). ARR analysis indicated that high fasting insulin and BMI added to age and sex as risk factors. Homeostatic model assessment of insulin resistance (HOMA-IR) did not associate with either cardiovascular endpoint in any model and smoking did not increase the risk conferred by high fasting insulin levels. Conclusions: Higher fasting insulin levels and increases in fasting insulin over time are associated with atherogenic progression and supersede BMI as well as HOMA-IR as risk factors.

High-Protein, Low-Glycaemic Meal Replacement Decreases Fasting Insulin and Inflammation Markers-A 12-Month Subanalysis of the ACOORH Trial.

Lifestyle interventions, including meal replacement, are effective in the prevention and treatment of type-2-diabetes and obesity. Since insulin is the key weight regulator, we hypothesised that the addition of meal replacement to a lifestyle intervention reduces insulin levels more effectively than lifestyle intervention alone. In the international multicentre randomised controlled ACOORH (Almased Concept against Overweight and Obesity and Related Health Risk) trial, overweight or obese persons who meet the criteria for metabolic syndrome (n = 463) were randomised into two groups. Both groups received nutritional advice focusing on carbohydrate restriction and the use of telemonitoring devices. The intervention group substituted all three main meals per day in week 1, two meals per day in weeks 2-4, and one meal per day in weeks 5-26 with a protein-rich, low-glycaemic meal replacement. Data were collected at baseline and after 1, 3, 6 and 12 months. All datasets providing insulin data (n = 446) were included in this predefined subanalysis. Significantly higher reductions in insulin (-3.3 ± 8.7 µU/mL vs. -1.6 ± 9.8 µU/mL), weight (-6.1 ± 5.2 kg vs. -3.2 ± 4.6 kg), and inflammation markers were observed in the intervention group. Insulin reduction correlated with weight reduction and the highest amount of weight loss (-7.6 ± 4.9 kg) was observed in those participants with an insulin decrease > 2 µU/mL. These results underline the potential for meal replacement-based lifestyle interventions in diabetes prevention, and measurement of insulin levels may serve as an indicator for adherence to carbohydrate restriction.

Effects of a Protein-Rich, Low-Glycaemic Meal Replacement on Changes in Dietary Intake and Body Weight Following a Weight-Management Intervention-The ACOORH Trial.

Although meal replacement can lead to weight reduction, there is uncertainty whether this dietary approach implemented into a lifestyle programme can improve long-term dietary intake. In this subanalysis of the Almased Concept against Overweight and Obesity and Related Health Risk (ACOORH) study (n = 463), participants with metabolic risk factors were randomly assigned to either a meal replacement-based lifestyle intervention group (INT) or a lifestyle intervention control group (CON). This subanalysis relies only on data of participants (n = 119) who returned correctly completed dietary records at baseline, and after 12 and 52 weeks. Both groups were not matched for nutrient composition at baseline. These data were further stratified by sex and also associated with weight change. INT showed a higher increase in protein intake related to the daily energy intake after 12 weeks (+6.37% [4.69; 8.04] vs. +2.48% [0.73; 4.23], p < 0.001) of intervention compared to CON. Fat and carbohydrate intake related to the daily energy intake were more strongly reduced in the INT compared to CON (both p < 0.01). After sex stratification, particularly INT-women increased their total protein intake after 12 (INT: +12.7 g vs. CON: -5.1 g, p = 0.021) and 52 weeks (INT: +5.7 g vs. CON: -16.4 g, p = 0.002) compared to CON. Protein intake was negatively associated with weight change (r = -0.421; p < 0.001) after 12 weeks. The results indicate that a protein-rich dietary strategy with a meal replacement can improve long-term nutritional intake, and was associated with weight loss.

Meal replacement by formula diet reduces weight more than a lifestyle intervention alone in patients with overweight or obesity and accompanied cardiovascular risk factors-the ACOORH trial.

BACKGROUND: As formula diets have demonstrated to be effective in reducing weight, we hypothesised that in patients with overweight or obesity and accompanied cardiovascular risk factors, combining a liquid formula diet with a lifestyle intervention is superior in reducing weight and improving cardiovascular risk factors than lifestyle intervention alone. METHODS: In this multicenter RCT 463 participants with overweight or obesity (BMI: 27-35 kg/m²; at least one additional co-morbidity of the metabolic syndrome) were randomised (1:2) into either a control group with lifestyle intervention only (CON, n = 155) or a lifestyle intervention group including a liquid meal replacement (INT, n = 308). Both groups used telemonitoring devices (scales and pedometers), received information on healthy diet and were instructed to increase physical activity. Telemonitoring devices automatically transferred data into a personalised online portal and acquired data were discussed. INT obtained a liquid meal replacement substituting three meals/day (~1200 kcal) within the first week. During weeks 2-4, participants replaced two meals/day and during weeks 5-26 only one meal/day was substituted (1300-1500 kcal/day). Follow-up was conducted after 52 weeks. Intention-to-treat analyses were performed. Primary outcome was weight change. Secondary outcomes comprised changes in cardiometabolic risk factors including body composition and laboratory parameters. RESULTS: From the starting cohort 360 (78%, INT: n = 244; CON: n = 116) and 317 (68%, INT: n = 216; CON: n = 101) participants completed the 26-weeks intervention phase and the 52-weeks follow-up. The estimated treatment difference (ETD) between both groups was -3.2 kg [-4.0; -2.5] (P < 0.001) after 12 weeks and -1.8 kg [-2.8; -0.8] (P < 0.001) after 52 weeks. CONCLUSIONS: A low-intensity lifestyle intervention combined with a liquid meal replacement is superior regarding weight reduction and improvement of cardiovascular risk factors than lifestyle intervention alone.