Petter Bjornstad

Age-related consequences of childhood obesity.

The severity and frequency of childhood obesity has increased significantly over the past three to four decades. The health effects of increased body mass index as a child may significantly impact obese youth as they age. However, many of the long-term outcomes of childhood obesity have yet to be studied. This article examines the currently available longitudinal data evaluating the effects of childhood obesity on adult outcomes. Consequences of obesity include an increased risk of developing the metabolic syndrome, cardiovascular disease, type 2 diabetes and its associated retinal and renal complications, nonalcoholic fatty liver disease, obstructive sleep apnea, polycystic ovarian syndrome, infertility, asthma, orthopedic complications, psychiatric disease, and increased rates of cancer, among others. These disorders can start as early as childhood, and such early onset increases the likelihood of early morbidity and mortality. Being obese as a child also increases the likelihood of being obese as an adult, and obesity in adulthood also leads to obesity-related complications. This review outlines the evidence for childhood obesity as a predictor of adult obesity and obesity-related disorders, thereby emphasizing the importance of early intervention to prevent the onset of obesity in childhood.

Sodium Glucose Cotransporter-2 Inhibition in Heart Failure: Potential Mechanisms, Clinical Applications, and Summary of Clinical Trials.

Despite current established therapy, heart failure (HF) remains a leading cause of hospitalization and mortality worldwide. Novel therapeutic targets are therefore needed to improve the prognosis of patients with HF. The EMPA-REG OUTCOME trial ([Empagliflozin] Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) demonstrated significant reductions in mortality and HF hospitalization risk in patients with type 2 diabetes mellitus (T2D) and cardiovascular disease with the antihyperglycemic agent, empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor. The CANVAS trial (Canagliflozin Cardiovascular Assessment Study) subsequently reported a reduction in 3-point major adverse cardiovascular events and HF hospitalization risk. Although SGLT2 inhibition may have potential application beyond T2D, including HF, the mechanisms responsible for the cardioprotective effects of SGLT2 inhibitors remain incompletely understood. SGLT2 inhibition promotes natriuresis and osmotic diuresis, leading to plasma volume contraction and reduced preload, and decreases in blood pressure, arterial stiffness, and afterload as well, thereby improving subendocardial blood flow in patients with HF. SGLT2 inhibition is also associated with preservation of renal function. Based on data from mechanistic studies and clinical trials, large clinical trials with SGLT2 inhibitors are now investigating the potential use of SGLT2 inhibition in patients who have HF with and without T2D. Accordingly, in this review, we summarize the key pharmacodynamic effects of SGLT2 inhibitors and the clinical evidence that support the rationale for the use of SGLT2 inhibitors in patients with HF who have T2D. Because these favorable effects presumably occur independent of blood glucose lowering, we also explore the potential use of SGLT2 inhibition in patients without T2D with HF or at risk of HF, such as in patients with coronary artery disease or hypertension. Finally, we provide a detailed overview and summary of ongoing cardiovascular outcome trials with SGLT2 inhibitors.

Early Diabetic Nephropathy in Type 1 Diabetes – New Insights

Purpose of review Despite improvements in glycemic and blood pressure control in patients with type 1 diabetes, diabetic nephropathy remains the most common cause of chronic kidney disease worldwide. A major challenge in preventing diabetic nephropathy is the inability to identify high-risk patients at an early stage, emphasizing the importance of discovering new therapeutic targets and implementation of clinical trials to reduce diabetic nephropathy risk. Recent findings Limitations of managing patients with diabetic nephropathy with renin–angiotensin–aldosterone system blockade have been identified in recent clinical trials, including the failure of primary prevention studies in T1D and the demonstration of harm with dual renin–angiotensin–aldosterone system blockade. Fortunately, several new targets, including serum uric acid, insulin sensitivity, vasopressin, and sodium-glucose cotransporter-2 inhibition, are promising in the prevention and treatment of diabetic nephropathy. Summary Diabetic nephropathy is characterized by a long clinically silent period without signs or symptoms of disease. There is an urgent need for improved methods of detecting early mediators of renal injury, to ultimately prevent the initiation and progression of diabetic nephropathy. In this review, we will focus on early diabetic nephropathy and summarize potential new therapeutic targets.

Fructose and uric acid in diabetic nephropathy

Clinical studies have reported associations between serum uric acid levels and the development of diabetic nephropathy, but the underlying mechanisms remain elusive. There is evidence from animal studies that blocking uric acid production protects the kidney from tubulointerstitial injury, which may suggest a causal role for uric acid in the development of diabetic tubular injury. In turn, when fructose, which is endogenously produced in diabetes via the polyol pathway, is metabolised, uric acid is generated from a side-chain reaction driven by ATP depletion and purine nucleotide turnover. For this reason, uric acid derived from endogenous fructose could cause tubulointerstitial injury in diabetes. Accordingly, our research group recently demonstrated that blocking fructose metabolism in a diabetic mouse model mitigated the development of tubulointerstitial injury by lowering tubular uric acid production. In this review we discuss the relationship between uric acid and fructose as a novel mechanism for the development of diabetic tubular injury.

Early Diabetic Nephropathy: A complication of reduced insulin sensitivity in type 1 diabetes

OBJECTIVE Diabetic nephropathy (DN) is a major cause of mortality in type 1 diabetes. Reduced insulin sensitivity is a well-documented component of type 1 diabetes. We hypothesized that baseline insulin sensitivity would predict development of DN over 6 years. RESEARCH DESIGN AND METHODS We assessed the relationship between insulin sensitivity at baseline and development of early phenotypes of DN—microalbuminuria (albumin-creatinine ratio [ACR] ≥30 mg/g) and rapid renal function decline (glomerular filtration rate [GFR] loss >3 mL/min/1.73 m2 per year)—with three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations over 6 years. Subjects with diabetes (n = 449) and without diabetes (n = 565) in the Coronary Artery Calcification in Type 1 Diabetes study had an estimated insulin sensitivity index (ISI) at baseline and 6-year follow-up. RESULTS The ISI was lower in subjects with diabetes than in those without diabetes (P < 0.0001). A higher ISI at baseline predicted a lower odds of developing an ACR ≥30 mg/g (odds ratio 0.65 [95% CI 0.49–0.85], P = 0.003) univariately and after adjusting for HbA1c (0.69 [0.51–0.93], P = 0.01). A higher ISI at baseline conferred protection from a rapid decline of GFR as assessed by CKD-EPI cystatin C (0.77 [0.64–0.92], P = 0.004) and remained significant after adjusting for HbA1c and age (0.80 [0.67–0.97], P = 0.02). We found no relation between ISI and rapid GFR decline estimated by CKD-EPI creatinine (P = 0.38) or CKD-EPI combined cystatin C and creatinine (P = 0.50). CONCLUSIONS Over 6 years, a higher ISI independently predicts a lower odds of developing microalbuminuria and rapid GFR decline as estimated with cystatin C, suggesting a relationship between insulin sensitivity and early phenotypes of DN.

Rapid GFR decline is associated with renal hyperfiltration and impaired GFR in adults with Type 1 diabetes

BACKGROUND Rapid glomerular filtration rate (GFR) decline (>3 mL/min/1.73 m(2)) is an increasingly recognized high-risk diabetic nephropathy (DN) phenotype in Type 1 diabetes. Rapid GFR decline is a recognized predictor of impaired GFR (<60 mL/min/1.73 m(2)). However, the association between rapid GFR decline and renal hyperfiltration is not well described in Type 1 diabetes. We hypothesized that renal hyperfiltration (estimated glomerular filtration rate, eGFR ≥ 120 mL/min/1.73 m(2)) would predict rapid GFR decline over 6 years and that rapid GFR decline would predict impaired GFR at 6 years in adults with Type 1 diabetes. METHODS GFR was calculated by chronic kidney disease epidemiology (CKD-EPI) creatinine in 646 adults with Type 1 diabetes in the coronary artery calcification in Type 1 diabetes study. Logistic multivariable models were employed to investigate the relationships between renal hyperfiltration and rapid GFR decline, and rapid GFR decline and incident impaired GFR over 6 years. RESULTS Renal hyperfiltration predicted greater odds of rapid GFR decline over 6 years [odds ratio (OR): 5.00, 95% confidence interval (CI): 3.03-8.25, P < 0.0001] adjusting for hemoglobin A1c (HbA1c), systolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), sex, duration, log of albumin/creatinine ratio and estimated insulin sensitivity. Furthermore, rapid GFR decline predicted greater odds of incident impaired eGFR (OR: 15.99, 95% CI 2.34-114.37, P = 0.006) in a similarly adjusted model. Sensitivity analyses with GFR calculated by CKD-EPI combined creatinine and cystatin C, and renal hyperfiltration defined as ≥135 mL/min/1.73 m(2) yielded similar results. CONCLUSIONS In adults with Type 1 diabetes, rapid GFR decline over 6 years was associated with baseline renal hyperfiltration and incident GFR impairment. These observations may suggest an intermediate and predictive role of rapid GFR decline in the progression of DN.

Serum uric acid and insulin sensitivity in adolescents and adults with and without type 1 diabetes

HYPOTHESIS Decreased insulin sensitivity (IS) exists in type 1 diabetes. Serum uric acid (SUA), whose concentration is related to renal clearance, predicts vascular complications in type 1 diabetes. SUA is also inversely associated with IS in non-diabetics, but has not been examined in type 1 diabetes. We hypothesized SUA would be associated with reduced IS in adolescents and adults with type 1 diabetes. METHODS The cross-sectional and longitudinal associations of SUA with IS were investigated in 254 adolescents with type 1 diabetes and 70 without in the Determinants of Macrovascular Disease in Adolescents with Type 1 Diabetes Study, and in 471 adults with type 1 diabetes and 571 without in the Coronary Artery Calcification in Type 1 diabetes (CACTI) study. RESULTS SUA was lower in subjects with type 1 diabetes (p<0.0001), but still remained inversely associated with IS after multivariable adjustments in adolescents (β±SE: -1.99±0.62, p=0.001, R2 =2%) and adults (β±SE: -0.91±0.33, p=0.006, R2 = 6%) with type 1 diabetes, though less strongly than in non-diabetic controls (adolescents: β±SE: -2.70±1.19, p=0.03, R2 = 15%, adults: β±SE: -5.99±0.75, p<0.0001, R2 =39%). CONCLUSION We demonstrated a significantly weaker relationship between SUA and reduced IS in subjects with type 1 diabetes than non-diabetic controls.

Asymptomatic Hyperuricemia Without Comorbidities Predicts Cardiometabolic Diseases: Five-Year Japanese Cohort Study

Whether asymptomatic hyperuricemia in the absence of comorbidities increases the risk for cardiometabolic disorders and chronic kidney disease remains controversial. This study was conducted to clarify the association between asymptomatic hyperuricemia and cardiometabolic conditions. Subjects consisting of Japanese adults between 30 and 85 years of age were enrolled in the study at Center for Preventive Medicine, St Luke’s International Hospital, Tokyo, and were available at enrollment (2004) and at 5-year follow-up (2009). Subjects were excluded if they were overweight or obese, hypertensive, diabetic, and dyslipidemic, had a history of gout or hyperuricemia on medications, or had chronic kidney disease as estimated glomerular filtration rate <60 mL/min per 1.73 m2. Linear and logistic regression analyses were used to examine the relationship between hyperuricemia and development of hypertension, diabetes mellitus, dyslipidemia, chronic kidney disease, and overweight/obesity (unadjusted and adjusted for age, sex, smoking, drinking habits, baseline estimated glomerular filtration rate, and body mass index). Five thousand eight hundred and ninety-nine subjects without comorbidities (mean age of 47±10 years, 1864 men) were followed for 5 years. Hyperuricemia (defined as >7 mg/dL in men and ≥6 mg/dL in women) was associated with increased cumulative incidence of hypertension (14.9% versus 6.1%; P<0.001), dyslipidemia (23.1% versus 15.5%; P<0.001), chronic kidney disease (19.0% versus 10.7%; P<0.001), and overweight/obesity (8.9% versus 3.0%; P<0.001), while diabetes mellitus (1.7% versus 0.9%; P=0.087) showed a trend but did not reach statistical significance. In conclusion, asymptomatic hyperuricemia carries a significant risk for developing cardiometabolic conditions in Japanese individual without comorbidities.

Elevated Serum Uric Acid Level Predicts Rapid Decline in Kidney Function

Background: While elevated serum uric acid level (SUA) is a recognized risk factor for chronic kidney disease, it remains unclear whether change in SUA is independently associated with change in estimated glomerular filtration rate (eGFR) over time. Accordingly, we examined the longitudinal associations between change in SUA and change in eGFR over 5 years in a general Japanese population. Methods: This was a large, single-center, retrospective 5-year cohort study at St. Lukes International Hospital, Tokyo, Japan, between 2004 and 2009. We included 13,070 subjects (30-85 years) in our analyses whose data were available between 2004 and 2009. Of those, we excluded 492 subjects with eGFR <60 mL/min/1.73 m2 at baseline. In addition to examining the entire cohort (n = 12,578), we stratified our analyses by baseline eGFR groups: 60-90, 90-120, and ≥120 mL/min/1.73 m2. Linear and logistic regressions models were applied to examine the relationships between baseline and change in SUA, change in eGFR, and rapid eGFR decline (defined as the highest quartile of change in eGFR), adjusted for age, gender, body mass index, abdominal circumference, hypertension, dyslipidemia, and diabetes mellitus. Results: After multivariable adjustments including baseline eGFR, 1 mg/dL increase in baseline SUA was associated with greater odds of developing rapid eGFR decline (OR 1.27, 95% CI 1.17-1.38), and 1 mg/dL increase in SUA over 5 years was associated with 3.77-fold greater odds of rapid eGFR decline (OR 3.77, 95% CI 3.35-4.26). Conclusions: Elevated baseline SUA and increasing SUA over time were independent risk factors for rapid eGFR decline over 5 years.

Insulin Sensitivity Is an Important Determinant of Renal Health in Adolescents With Type 2 Diabetes

OBJECTIVE Diabetic nephropathy (DN) remains the most common cause of end-stage renal disease and is a major cause of mortality in type 2 diabetes. Insulin sensitivity is an important determinant of renal health in adults with type 2 diabetes, but limited data exist in adolescents. We hypothesized that measured insulin sensitivity (glucose infusion rate [GIR]) would be associated with early markers of DN reflected by estimated glomerular filtration rate (eGFR) and albumin-creatinine ratio (ACR) in adolescents with type 2 diabetes. RESEARCH DESIGN AND METHODS Type 2 diabetic (n = 46), obese (n = 29), and lean (n = 19) adolescents (15.1 ± 2.2 years) had GIR measured by hyperinsulinemic-euglycemic clamps. ACR was measured and GFR was estimated by the Bouvet equation (combined creatinine and cystatin C). RESULTS Adolescents with type 2 diabetes had significantly lower GIR, and higher eGFR and ACR than obese or lean adolescents. Moreover, 34% of type 2 diabetic adolescents had albuminuria (ACR ≥30 mg/g), and 24% had hyperfiltration (≥135 mL/min/1.73 m2). Stratifying ACR and eGFR into tertiles, adolescents with type 2 diabetes in the highest tertiles of ACR and eGFR had respectively lower GIR than those in the mid and low tertiles, after adjusting for age, sex, Tanner stage, BMI, and HbA1c (P = 0.02 and P = 0.04). GIR, but not HbA1c, LDL, or systolic blood pressure, was also associated with eGFR after adjusting for sex and Tanner stage (β ± SE: −2.23 ± 0.87; P = 0.02). CONCLUSIONS A significant proportion of adolescents with type 2 diabetes showed evidence of early DN, and insulin sensitivity, rather than HbA1c, blood pressure, or lipid control, was the strongest determinant of renal health.