Sexual dimorphism in insulin sensitivity in adolescents with insulin-dependent diabetes mellitus

Early weight gain after diagnosis may have an impact on remission status in children with new-onset type 1 diabetes mellitus

BACKGROUND

Residual beta-cell function and improvement in insulin sensitivity by reversal of glucose toxicity are two phenomena thought to be related to partial remission (PR). Body fat mass is the major determinant of insulin sensitivity. The aim of this study is to investigate the relationship between the rate of body weight gain after diagnosis of type 1 diabetes mellitus (T1DM) and other clinical factors for the development and duration of PR.

METHODS

Children (2-16 years) with new-onset T1DM (n = 99) were grouped into remitters and non-remitters by using insulin dose-adjusted glycosylated hemoglobin (HbA1c) values. Laboratory and clinical data as well as daily insulin requirement per kilogram of body weight at diagnosis and each visit were recorded, and the duration of PR was determined. Changes in body mass index standard deviation score (BMI-SDS) were calculated by the auxological data collected every 6 months.

RESULTS

There were 47 remitters (47.5%) and 52 (52.5%) non-remitters. The mean increase in BMI-SDS at the first 6 months of diagnosis was higher in the non-remitters than in the remitters (p = 0.04). Duration of PR was negatively correlated with the change in BMI-SDS between 6 and 12 months after diagnosis. Male sex, younger age, prepubertal status, and lower HbA1c were predictors of remission, among which male sex had the highest chance by multivariate regression.

CONCLUSIONS

Early rapid weight gain after diagnosis of T1DM may play a role in the lack of remission and shorter duration of PR. Interventions to prevent early rapid weight gain can maintain the development and prolongation of remission.

Markers of Glucagon Resistance Improve With Reductions in Hepatic Steatosis and Body Weight in Type 2 Diabetes

Context

Hyperglucagonemia may develop in type 2 diabetes due to obesity-prone hepatic steatosis (glucagon resistance). Markers of glucagon resistance (including the glucagon-alanine index) improve following diet-induced weight loss, but the partial contribution of lowering hepatic steatosis vs body weight is unknown.

Objective

This work aimed to investigate the dependency of body weight loss following a reduction in hepatic steatosis on markers of glucagon resistance in type 2 diabetes.

Methods

A post hoc analysis was conducted from 2 previously published randomized controlled trials. We investigated the effect of weight maintenance (study 1: isocaloric feeding) or weight loss (study 2: hypocaloric feeding), both of which induced reductions in hepatic steatosis, on markers of glucagon sensitivity, including the glucagon-alanine index measured using a validated enzyme-linked immunosorbent assay and metabolomics in 94 individuals (n = 28 in study 1; n = 66 in study 2). Individuals with overweight or obesity with type 2 diabetes were randomly assigned to a 6-week conventional diabetes (CD) or carbohydrate-reduced high-protein (CRHP) diet within both isocaloric and hypocaloric feeding-interventions.

Results

By design, weight loss was greater after hypocaloric compared to isocaloric feeding, but both diets caused similar reductions in hepatic steatosis, allowing us to investigate the effect of reducing hepatic steatosis with or without a clinically relevant weight loss on markers of glucagon resistance. The glucagon-alanine index improved following hypocaloric, but not isocaloric, feeding, independently of macronutrient composition.

Conclusion

Improvements in glucagon resistance may depend on body weight loss in patients with type 2 diabetes.

Effects of Type 1 Diabetes Mellitus on Linear Growth: A Comprehensive Review

Type 1 diabetes mellitus (T1DM) has a significant effect on the growth of children. The disease has a negative effect on growth when considered in relation to the time period and metabolic control. Studies in this review have suggested debilitated growth in children with T1DM and have a few anomalies in the growth hormone (GH)-insulin-like growth factor-1 (IGF-1) axis when compared to fit children. Some studies show that children with T1DM were taller before the onset of the disease and during early diagnosis. Moreover, the linear growth depends on the interaction between the gonadotropin hormone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex steroid hormones axis and GH-IGF-1; there's a rise in GH during puberty, which has an effect on the estrogen and testosterone, which leads to the pulsatile secretion of GH, this increment leads to insulin resistance. These studies suggest short stature in girls, and some suggest in both. The final height in boys was unchanged, but a slight decline was observed in girls. This review aims to provide the latest understanding of impaired height in children with T1DM. The most accepted and effective treatment of impaired growth is the administration of long-acting insulin or continuous rapid-acting insulin. However, height was affected by the administration of good basal insulin at puberty and was unaffected by the continuous subcutaneous insulin injection. Hence, new technologies are the therapeutic regimen in children, especially the prepubertal age group; it will be interesting to see their effects on growth patterns in these children with T1DM.

Reduced intestinal lipid absorption improves glucose metabolism in aged G2-Terc knockout mice

BACKGROUND

Biological aging is an important factor leading to the development of pathologies associated with metabolic dysregulation, including type 2 diabetes, cancer, cardiovascular and neurodegenerative diseases. Telomere length, a central feature of aging, has additionally been identified as inversely associated with glucose tolerance and the development of type 2 diabetes. However, the effects of shortened telomeres on body weight and metabolism remain incompletely understood. Here, we studied the metabolic consequences of moderate telomere shortening using second generation loss of telomerase activity in mice.

RESULTS

Aged male and female G2 Terc-/- mice and controls were characterized with respect to body weight and composition, glucose homeostasis, insulin sensitivity and metabolic activity. This was complemented with molecular and histological analysis of adipose tissue, liver and the intestine as well as microbiota analysis. We show that moderate telomere shortening leads to improved insulin sensitivity and glucose tolerance in aged male and female G2 Terc-/- mice. This is accompanied by reduced fat and lean mass in both sexes. Mechanistically, the metabolic improvement results from reduced dietary lipid uptake in the intestine, characterized by reduced gene expression of fatty acid transporters in enterocytes of the small intestine. Furthermore, G2-Terc-/- mice showed significant alterations in the composition of gut microbiota, potentially contributing to the improved glucose metabolism.

CONCLUSIONS

Our study shows that moderate telomere shortening reduces intestinal lipid absorption, resulting in reduced adiposity and improved glucose metabolism in aged mice. These findings will guide future murine and human aging studies and provide important insights into the age associated development of type 2 diabetes and metabolic syndrome.

Comparing the Fasting and Random-Fed Metabolome Response to an Oral Glucose Tolerance Test in Children and Adolescents: Implications of Sex, Obesity, and Insulin Resistance

As the incidence of obesity and type 2 diabetes (T2D) is occurring at a younger age, studying adolescent nutrient metabolism can provide insights on the development of T2D. Metabolic challenges, including an oral glucose tolerance test (OGTT) can assess the effects of perturbations in nutrient metabolism. Here, we present alterations in the global metabolome in response to an OGTT, classifying the influence of obesity and insulin resistance (IR) in adolescents that arrived at the clinic fasted and in a random-fed state. Participants were recruited as lean (n = 55, aged 8–17 years, BMI percentile 5–85%) and overweight and obese (OVOB, n = 228, aged 8–17 years, BMI percentile ≥ 85%). Untargeted metabolomics profiled 246 annotated metabolites in plasma at t0 and t60 min during the OGTT. Our results suggest that obesity and IR influence the switch from fatty acid (FA) to glucose oxidation in response to the OGTT. Obesity was associated with a blunted decline of acylcarnitines and fatty acid oxidation intermediates. In females, metabolites from the Fasted and Random-Fed OGTT were associated with HOMA-IR, including diacylglycerols, leucine/isoleucine, acylcarnitines, and phosphocholines. Our results indicate that at an early age, obesity and IR may influence the metabolome dynamics in response to a glucose challenge.

Features of partial remission in children with type 1 diabetes using the insulin dose-adjusted A1c definition and risk factors associated with nonremission

PURPOSE

We sought to evaluate features of partial remission (PR) in children with type 1 diabetes mellitus (T1DM) using the insulin-dose adjusted A1c (IDAA1c) definition and to identify risk factors associated with nonremission.

METHODS

Medical records of patients with newly diagnosed T1DM between January 1, 2008, and June 30, 2018, were retrospectively reviewed. Hemoglobin A1c (HbA1c) readings and insulin total daily doses (TDDs) of each patient at each follow-up visit were obtained with IDAA1c values calculated. PR was defined as an IDAA1c score of 9 points or less within 6 months of diagnosis. The trends of HbA1c and TDD within 2 years after diagnosis were compared between remitters and nonremitters. Factors that may predict the occurrence of PR were studied, with their relative risks of nonremission calculated.

RESULTS

PR occurred in 26 patients (45.6%), including 8 girls and 18 boys, with a median duration of 8 months. The frequency of remission in male patients was significantly higher (P=0.002) and the relative risk of female sex with nonremission was 2.20 (95% confidence interval [CI], 1.24-3.91), which remained significant when adjusted by multivariate regression modeling. The initial HbA1c level at diagnosis was also significantly higher in the nonremission group (P=0.029), with a relative risk of 1.12 (95% CI, 1.01-1.25). Both HbA1c (P=0.012) and TDD (P=0.006) were significantly lower within 2 years after diagnosis among remitters than in nonremitters. TDD was significantly lower in male patients (P=0.029) during the same period, while there was no significant difference in HbA1c level between male and female patients (P=0.163).

CONCLUSION

Both the initial HbA1c level at diagnosis and sex were factors associated with the occurrence of PR. Female sex was an independent risk factor of nonremission, likely resulting from a higher insulin requirement in female T1DM patients.

Metabolic and biological changes in children with obesity and diabetes

The World Health Organization has stated that obesity in childhood is one of the most serious public health challenges of the 21^st century. Overweightness and obesity in early childhood lead to a higher risk of overweightness and obesity in adulthood, thus conferring an increased risk of chronic inflammatory conditions, including type 2 diabetes mellitus, cardiovascular diseases, non-alcoholic fatty liver disease, and some cancers. Therefore, metabolome analysis, targeted at screening and intervening in childhood obesity, is very important. Recent studies have indicated that amino acid and lipid metabolism could influence metabolic pathways in children with obesity. For this review, we searched clinical data addressing metabolomic profiles and insulin resistance (IR) in children with obesity from inception to February 2021 in Medline, Web of Science, and Scopus. According to our search, branched-chain amino acids (BCAAs), aromatic amino acids, and acylcarnitines have reportedly been associated with IR as biomarkers for diabetes in children. BCAAs, tyrosine, and phenylalanine could be predictors of the future development of diabetes in nondiabetic subjects. In addition, it is well known that insulin regulates BCAA metabolism, and BCAA is a biomarker for IR. To interpret the mechanism behind metabolic changes in obesity, it is very important to understand the pathways and combinations related with amino acid, lipid and glucose metabolism. In this review, we summarize studies on metabolic changes to understand metabolomics in children with obesity.

An improved clinical model to predict stimulated C-peptide in children with recent-onset type 1 diabetes

BACKGROUND

Stimulated C-peptide measurement after a mixed meal tolerance test (MMTT) is the accepted gold standard for assessing residual beta-cell function in type 1 diabetes (T1D); however, this approach is impractical outside of clinical trials.

OBJECTIVE

To develop an improved estimate of residual beta-cell function in children with T1D using commonly measured clinical variables.

SUBJECTS/METHODS

A clinical model to predict 90-minute MMTT stimulated C-peptide in children with recent-onset T1D was developed from the combined AbATE, START, and TIDAL placebo subjects (n = 46) 6 months post-recruitment using multiple linear regression. This model was then validated in a clinical cohort (Hvidoere study group, n = 262).

RESULTS

A model of estimated C-peptide at 6 months post-diagnosis, which included age, gender, body mass index (BMI), hemoglobin A1c (HbA1c), and insulin dose predicted 90-minute stimulated C-peptide measurements (adjusted R²  = 0.63, P < 0.0001). The predictive value of insulin dose and HbA1c alone (IDAA1c) for 90-minute stimulated C-peptide was significantly lower (R^{2 =} 0.37, P < 0.0001). The slopes of linear regression lines of the estimated and stimulated 90-minute C-peptide levels obtained at 6 and 12 months post diagnosis in the Hvidoere clinical cohort were R²  = 0.36, P < 0.0001 at 6 months and R²  = 0.37, P < 0.0001 at 12 months.

CONCLUSIONS

A clinical model including age, gender, BMI, HbA1c, and insulin dose predicts stimulated C-peptide levels in children with recent-onset T1D. Estimated C-peptide is an improved surrogate to monitor residual beta-cell function outside clinical trial settings.

Sex as a determinant of type 1 diabetes at diagnosis

OBJECTIVE

The present study tested the hypothesis that girls have a more aggressive disease process than boys at the diagnosis of type 1 diabetes (T1D).

METHODS

Demographic and clinical characteristics, the humoral autoantibody profile, and the genetic risk assessed by the presence of human leukocyte antigen DR-DQ haplotypes were analyzed in terms of sex in 4993 children and adolescents diagnosed with T1D between January 2003 and December 2016.

RESULTS

A clear male preponderance (56.6%) was observed in our cohort and boys were significantly older than girls at clinical diagnosis (mean 8.3 vs 7.7 years, P < .001). Age-adjusted analyses showed a poorer metabolic decompensation in girls than boys at diagnosis. Boys tested more often positive for autoantibodies against insulin autoantibodies (P = .008), islet antigen-2 autoantibodies (P = .033), and zinc transporter 8 autoantibodies (P = .027), whereas girls had a higher frequency of glutamic acid decarboxylase autoantibodies (GADA) (P < .001) and higher GADA (P < .001) and islet cell antibody titers (P = .001). We did not find any significant differences in the genetic risk profile between girls and boys.

CONCLUSIONS

Our data show that the metabolic derangement is more severe in girls already at diagnosis of T1D and this finding is independent of age. The immunologic aggressiveness of the disease is more variable as the predominance of different autoantibodies varies between sexes with a higher frequency of GADA in girls, while the 3 other biochemical autoantibodies were more common in boys.

Current use of metformin in addition to insulin in pediatric patients with type 1 diabetes mellitus: an analysis based on a large diabetes registry in Germany and Austria

BACKGROUND

With increasing obesity in childhood and adolescence, weight gain, and insulin resistance become also more frequent in patients with type 1 diabetes mellitus (T1DM). Especially during puberty, insulin therapy often has to be intensified and higher insulin doses are necessary. Some studies point to a beneficial effect of metformin in addition to insulin in these patients. In order to describe current practice and possible benefits, we compared pediatric T1DM patients with insulin plus metformin (n = 525) to patients with insulin therapy only (n = 57 487) in a prospective multicenter analysis.

METHODS

Auxological and treatment data from 58 012 patients aged <21 yr with T1DM in the German/Austrian Diabetes Patienten Verlaufsdokumentation (DPV) registry were analyzed by multivariable mixed regression modeling.

RESULTS

Patients with additional metformin were older [median (interquartile range)]: [16.1 (14.1-17.6) vs. 15.2 (11.5-17.5) yr] with female preponderance (61.0 vs. 47.2%, p < 0.01). They had higher body mass index-standard deviation score (BMI-SDS) [+2.03 (+1.29 to +2.56) vs. +0.51 (-0.12 to +1.15); p < 0.01] and glycated hemoglobin (HbA1c) (9.0 vs. 8.6%, p < 0.01). Hypertension (43.7 vs. 24.8%) and dyslipidemia (58.4 vs. 40.6%) were significantly more prevalent. Adjusted insulin dose was significantly higher (0.98 vs. 0.93 IU/kg bodyweight). In a subgroup of 285 patients followed-up longitudinally (average treatment period 1.42 yr), addition of metformin resulted in a slight reduction of BMI-SDS [-0.01 (-2.01 to +1.40)], but did not improve HbA1c or insulin requirement.

CONCLUSION

Additional metformin therapy in T1DM is primarily used in obese females. Additional therapy with metformin was associated with minor benefits.

Prevalence of overweight, obesity and metabolic syndrome components in children, adolescents and young adults with type 1 diabetes mellitus

BACKGROUND

We aimed to determine the prevalence of overweight and obesity among children, adolescents and young adults with type 1 diabetes mellitus (T1DM), and to assess the prevalence of the metabolic syndrome and its components.

METHODS

The study cohort comprised 326 (168 women) consecutive patients aged 5 to 30 years diagnosed with T1DM and followed up in the Juvenile Diabetes Clinic, Maccabi Health Care Services. Anthropometric measurements, blood pressure, presence of additional diseases, other medications, HbA1c , triglycerides and high density lipoprotein cholesterol levels were obtained.

RESULTS

The mean age in the study group was 18.5 ± 6.0 years, and the mean diabetes duration was 8.7 ± 5.0 years. Mean HbA1c level was 8.1 ± 1.3%. Nineteen per cent of the study population was overweight (85th > body mass index < 95th percentile) and 5.2% was obese (body mass index ≥ 95th percentile). Female patients aged 15 ≤ 18 and 18 ≤ 25 years were significantly overweight compared with healthy Israeli women in the same age groups, 33.3% versus 12.7% and 26.3% versus 7.8%, respectively, p < 0001. There were no obese female patients in the 15 ≤ 18 age group. Among the men in all age groups, there was no difference in the prevalence of overweight and obesity compared with healthy men in the general population. There was no difference in the age of onset, disease duration, HbA1c levels, treatment with anti-depressants and associated morbidities between the normal weight, overweight and obese groups. Obese patients had lower levels of HDL and increased prevalence of hypertension and metabolic syndrome.

CONCLUSIONS

Overweight but not obesity was more prevalent in women with T1DM. Metabolic syndrome and its components were more prevalent among overweight and obese individuals with T1DM than among normal weight individuals.

Sex-associated differences in free fatty acid flux of obese adolescents

CONTEXT

In obesity, increases in free fatty acid (FFA) flux can predict development of insulin resistance. Adult women release more FFA relative to resting energy expenditure (REE) and have greater FFA clearance rates than men. In adolescents, it is unknown whether sex differences in FFA flux occur.

OBJECTIVE

Our objective was to determine the associations of sex, REE, and body composition with FFA kinetics in obese adolescents.

PARTICIPANTS

Participants were from a convenience sample of 112 non-Hispanic white and black adolescents (31% male; age range, 12-18 years; body mass index SD score range, 1.6-3.1) studied before initiating obesity treatment.

MAIN OUTCOME MEASURES

Glucose, insulin, and FFA were measured during insulin-modified frequently sampled iv glucose tolerance tests. Minimal models for glucose and FFA calculated insulin sensitivity index (SI) and FFA kinetics, including maximum (l0 + l2) and insulin-suppressed (l2) lipolysis rates, clearance rate constant (cf), and insulin concentration for 50% lipolysis suppression (ED50). Relationships of FFA measures to sex, REE, fat mass (FM), lean body mass (LBM) and visceral adipose tissue (VAT) were examined.

RESULTS

In models accounting for age, race, pubertal status, height, FM, and LBM, we found sex, pubertal status, age, and REE independently contributed to the prediction of l2 and l0 + l2 (P < .05). Sex and REE independently predicted ED50 (P < .05). Sex, FM/VAT, and LBM were independent predictors of cf. Girls had greater l2, l0 + l2 and ED50 (P < .05, adjusted for REE) and greater cf (P < .05, adjusted for FM or VAT) than boys.

CONCLUSION

Independent of the effects of REE and FM, FFA kinetics differ significantly in obese adolescent girls and boys, suggesting greater FFA flux among girls.

Gender-specific care of diabetes

Diabetic men have benefited in the last 30 years from a significant improvement in total and cardiovascular mortality, whereas diabetic women have had no improvement at all. Moreover, recent research focused on the role of sex hormones in glucose homeostasis, and might account for different pathophysiologic mechanisms in the development of diabetes-related complications. Thus, care of diabetic women is a challenge that requires particular attention. The available data regarding gender-specific care of diabetes mellitus are uneven, rich in some domains but very poor in others. The large prospective trials performed in the last 20 years have assumed that the natural history of diabetes mellitus in men and women, as well as the efficiency of glucose-lowering therapies and management of hyperglycemic-related complications, could be attributable without distinction to men and women. We propose in this paper to analyze the published medical literature according to the specific management of diabetes mellitus in women, and to try to distinguish some particular features. We found important distinctions between diabetic men and women regarding the patterns of abnormalities of glucose regulation, epidemiology, development of diabetes-related complications, ischemic heart disease, morbidity and mortality, impact of cardiovascular risk factors, development of the metabolic syndrome, depression and osteoporosis, as well as the impact of lifestyle modifications or primary and secondary preventions on cardiovascular risk factors, and finally medical therapeutics. Moreover, special considerations were given to some particular aspects of the medical life in diabetic women, such as the features of gestational diabetes mellitus and the management of pregnancy in pregestational diabetic women, use of contraception, hormone-replacement therapy and polycystic ovary syndrome.

Female reproduction and type 1 diabetes: from mechanisms to clinical findings

BACKGROUND

The functional reproductive alterations seen in women with type 1 diabetes (T1D) have changed as therapy has improved. Historically, patients with T1D and insufficient metabolic control exhibited a high prevalence of amenorrhea, hypogonadism and infertility. This paper reviews the impact of diabetes on the reproductive axis of female T1D patients treated with modern insulin therapy, with special attention to the mechanisms by which diabetes disrupts hypothalamic-pituitary-ovarian function, as documented mainly by animal model studies.

METHODS

A comprehensive MEDLINE search of articles published from 1966 to 2012 was performed. Animal model studies on experimental diabetes and human studies on T1D were examined and cross-referenced with terms that referred to different aspects of the gonadotropic axis, gonadotrophins and gonadal steroids.

RESULTS

Recent studies have shown that women with T1D still display delayed puberty and menarche, menstrual irregularities (especially oligomenorrhoea), mild hyperandrogenism, polycystic ovarian syndrome, fewer live born children and possibly earlier menopause. Animal models have helped us to decipher the underlying basis of these conditions and have highlighted the variable contributions of defective leptin, insulin and kisspeptin signalling to the mechanisms of perturbed reproduction in T1D.

CONCLUSIONS

Despite improvements in insulin therapy, T1D patients still suffer many reproductive problems that warrant specific diagnoses and therapeutic management. Similar to other states of metabolic stress, T1D represents a challenge to the correct functioning of the reproductive axis.

Left ventricular diastolic dysfunction in adolescents with type 1 diabetes reflects the long- but not short-term metabolic control

OBJECTIVE

The aim of this study was to compare the LV morphology and function in adolescents with DM1 and their healthy peers.

SUBJECTS AND METHODS

In 59 DM1 patients (30 girls, 29 boys,aged 14-17 years), and in control group (15 girls, 15 boys) LV was assessed by M-mode, 2D and Doppler echocardiography. The metabolic control was assessed in the long- (mean HbAlc value for the entire treatment period-HbA1c1), medium- (mean HbA1c for the past two pre-study years-HbA1c2), and short-term (HbA1c on the day of the study-HbA1c3).

RESULTS

Diabetic patients presented an increase of IRT (0.062 vs. 0.056 s, p < 0.05 in boys, and 0.062 vs. 0.056 s, p < 0.05 in girls), A wave (56.1 vs. 53.95 cm/s in boys, and 60.3 vs. 58 cm/s in girls), and deceleration time values (0.16 vs. 0.15 s in boys, and 0.17 vs. 0.15 s in girls), decrease of E wave (97.35 vs. 104.9 cm/s in boys, and 99.67 vs. 101.8 cm/s in girls), as well as the E/A ratio (1.79 vs. 2.0 in boys, and 1.7 vs. 1.78 in girls). The systolic function was normal. In girls there was a correlation between IRT and HbA1c1 and HbA1c2 (r = 0.42, r = 0.46, p < 0.05); between the A wave and HbA1c2 (r = 0.46, p < 0.05); between LV posterior wall systolic dimension and HbA1c1, HbA1c2 (r = 0.45, r = 0.41, p < 0.05), and in boys between the A wave and HbA1c1 and HbA1c2 (r = 0.48, p < 0.01; r = 0.37, p < 0.05).

CONCLUSIONS

Pubertal patients with DM1 demonstrate discrete impairment of the diastolic function beside normal systolic function of the LV. Further investigations are needed to assess the value of this observation. It seems that LV diastolic dysfunction in girls depends on the degree of insulin resistance and DM1 duration, and similarly as in boys, on the long-term metabolic control.

Gender-specific care of diabetes mellitus: particular considerations in the management of diabetic women

In the past 30 years, the all-cause mortality and cardiovascular mortality rates for women with diabetes mellitus (DM), in contrast to men, have not declined. Furthermore, the difference between all-cause mortality rates in women with DM and those without DM has more than doubled. This urgently needs addressing. This review will analyse published medical literature relating to the specific management of DM in women and try to identify areas where gender affects care. We have identified specific gender differences in the pathophysiology of glucose homeostasis disorder, diabetes-related complications and any female gender-specific features of women with diabetes, such as contraception and the menopause. These gender-specific features of DM may offer a route to improved care for women and new therapeutic possibilities.

Association between body mass index and core components of metabolic syndrome in 1486 patients with type 1 diabetes mellitus in Japan (JDDM 13)

There is no recent study on the prevalence of overweight and obesity in patients with type 1 diabetes mellitus (T1DM) in Japan. Being overweight has a significant effect on the metabolic condition and glycemic control of such patients. In the present cross-sectional study, we investigated the effects of body mass index (BMI) on lipid profile, blood pressure, and glycemic control in patients with T1DM. In total, 1486 patients with T1DM (including 401 patients with early onset T1DM who were <20 years of age at diagnosis) were included. Patients were divided into four groups according to their BMI, and glycosylated hemoglobin (HbA1c), daily insulin dose per kg body weight, lipid profile, and blood pressure were compared between groups. We found that 15.7% of all patients were overweight (BMI >or= 25.0 kg/m(2)) and 2.0% were obese (BMI >or= 30.0 kg/m(2)), compared with 17.5% and 2.0%, respectively, in the early onset T1DM subgroup. Significant changes in lipid profiles and blood pressure were found with increasing BMI in both the entire population and the early onset T1DM subgroup. In the entire study population HbA1c and the body weight-adjusted daily insulin dose were significantly higher in patients with a BMI >or= 23 kg/m(2) compared with those with a BMI<23 kg/m(2); however, this was not the case in the early onset T1DM subgroup. This difference may be due to the relatively small number of patients in that subgroup. In conclusion, the prevalence of overweight and obesity in patients with T1DM was less than that in the normal Japanese population. For patients with T1DM, being overweight was associated with higher blood pressure and dyslipidemia. Furthermore, we cannot exclude an association between being overweight and the need for higher daily doses of insulin.

Glycaemic control and diabetes care utilization in young adults with Type 1 diabetes

OBJECTIVES

To explore how glycaemic control in young adults is related to diabetes care utilization during the transition to adult diabetes care and if these variables differ between males and females.

METHODS

This is a retrospective, longitudinal design following patients' records from age 18-24 years. Adolescents (n = 104) connected to one paediatric outpatient clinic and referred to six different adult clinics were included. Data were collected regarding gender, age at diagnosis and transfer, yearly glycated haemoglobin (HbA(1c)) and body mass index, severe hypoglycaemia and diabetic ketoacidosis, retinopathy and diabetes care utilization.

RESULTS

HbA(1c) decreased over time in females (P = 0.004) but not in males. Less than 10% had HbA(1c) in the recommended range during the study period. The decrease in severe hypoglycaemia and diabetic ketoacidosis was not significant. The prevalence of background retinopathy increased from 5 to 29% during the study period (P < 0.001). Mean transfer age was 19.8 years. The youths visited the paediatric clinic more often than the adult clinic (P < 0.001) and females visited adult care more often than males (P = 0.04). There was a steady decrease in the number of visits/year over time (P < 0. 001). Poor glycaemic control was associated with more visits for both males and females (P = 0.005) in adult care.

CONCLUSIONS

As there was no gender difference in the relation between HbA(1c) and the number of visits in adult diabetes care, the higher frequency of visits in adult care for females cannot be solely explained by their glycaemic control. Gender differences regarding diabetes care utilization should be further explored.

Insulin sensitivity in Type 1 diabetic children and adolescents

AIM

To estimate insulin sensitivity in Type 1 diabetic children and adolescents, and assess the relationship between insulin sensitivity and clinical markers of adiposity and parameters of the metabolic syndrome.

METHODS

A total of 202 patients aged 8-18 years with Type 1 diabetes and disease duration 1.5-15 years participated. Insulin sensitivity was estimated by glucose uptake during an euglycaemic-hyperinsulinaemic clamp and was calculated as the average amount of glucose (M(lbm) = mg/kg(lbm)/min) required to maintain euglycaemia. Blood pressure, glycated haemoglobin (HbA(1c)) and lipid concentrations were measured.

RESULTS

The M(lbm )value ranged from 4.14 to 25.25 mg/kg(lbm)/min (mean 9.81 +/- 3.34 mg/kg(lbm)/min). There was a significant relationship between M value and patients' age (r = -0.38, P < 0.0001). Insulin sensitivity decreased significantly with the onset of puberty; hence, it was significantly lower in pubertal and post-pubertal adolescents. Girls were significantly more insulin resistant than boys (9.01 +/- 0.32 vs. 10.43 +/- 0.29 mg/kg(lbm)/min, P = 0.005). Insulin sensitivity correlated with body mass index (r = -0.29, P < 0.001), waist circumference (r = -0.35, P < 0.001), triceps skin fold (r = -0.17, P = 0.018), subscapular skin fold (r = -0.23, P = 0.001) and body fat (r = -0.19, P = 0.006). There was a relationship between M(lbm) value, cholesterol (r = -0.18, P = 0.012), high-density lipoprotein cholesterol (r = 0.15, P = 0.035), low-density lipoprotein cholesterol (r = -0.22, P = 0.002), triglycerides (r = -0.32, P < 0.001) and systolic blood pressure (r = -0.15, P = 0.029). Insulin resistance was related to HbA(1c) (r = -0.18, P = 0.012). Additionally, there was a correlation between M(lbm) value and insulin dose.

CONCLUSIONS

Children and adolescents with Type 1 diabetes mellitus have a very wide range of insulin sensitivity, which is determined by sex, age, amount of adipose tissue and glycaemic control.

Impaired endothelial function in healthy African-American adolescents compared with Caucasians

OBJECTIVE

To determine whether African-American adolescents have endothelial dysfunction compared with Caucasians and whether differences are a result of differences in insulin sensitivity calculated from total glucose (S(I)) or secretion.

STUDY DESIGN

Thirty-three Caucasian (13.6 +/- 2.6 years of age; body mass index [BMI] 21.6 +/- 4.4 kg/m2 mean +/- SD) and 25 African-American (13.3 +/- 2.9 years of age; BMI 24.0 +/- 4.4 kg/m2) adolescents were studied. Forearm blood flow (FBF; plethysmography) was measured before and after 5 minutes of arterial occlusion. S(I) and acute insulin response to glucose (AIRG) were measured using intravenous glucose tolerance tests and minimal modeling.

RESULTS

Baseline FBF did not differ between races. Postocclusion FBF was lower in African-Americans (17.2 +/- 1.2 vs 22.6 +/- 1.2 mL/dL/minute, P = .006). AIRG was higher in African-Americans (6050 +/- 940 vs 2410 +/- 30 microU minute/mL, P = .001). Pubertal stage had no effect. S(I) did not differ by race or pubertal stage. In African-Americans, percent fall in FVR following arterial occlusion correlated (r = 0.67, P = .001) with log AIRG. No relationships were found between percent fall in FVR and S(I) in either race.

CONCLUSION

African-American adolescents have decreased endothelial function. This may be a result of increased insulin secretion. Endothelial dysfunction in African-American adolescents may predispose to cardiovascular and type II diabetes.

Growth, puberty, and final height in children with Type 1 diabetes

OBJECTIVE

The aims of this study were to assess the physical growth and pubertal development in a group of diabetic children and to evaluate the effect of height at diagnosis, duration of illness, and degree of glycemic control on final height and sexual maturation.

RESEARCH DESIGN

A cohort of 72 Sudanese diabetic children, 7-13 years of age at diagnosis, was followed longitudinally from the onset of diabetes until the attainment of final height.

RESULTS

The mean height standard deviation scores (SDS) at diagnosis were 0.04 in boys and -0.15 in girls, which was greater than their genetic target height (GTH). The growth velocity between diagnosis and final height was slow, with significant reduction in pubertal growth spurt. The mean final height attained by these children was lower than their GTH, a finding that contradicts most of the recently published reports. The average age at menarche in girls (15.1 years) and the mean age of full sexual maturation in boys (17.2 years) were significantly delayed in this group of diabetic patients. This retardation in physical growth and pubertal development was positively correlated with the duration of diabetes before the onset of puberty and glycated haemoglobin (HbA1c) concentration. The majority of these patients were thin at diagnosis of diabetes, with median body mass index (BMI) <22, but showed a remarkable, progressive weight gain during puberty, which was more evident in girls. The weight gain was independent of weight at diagnosis and duration of diabetes, but was positively correlated with the daily dose of insulin and HbA1c concentration.

CONCLUSION

Conventional therapy of diabetic children is associated with impairment of physical growth and delayed sexual maturation.

Clamp techniques in paediatrics: what have we learned?

The marked increase in conditions associated with insulin resistance in youth, including obesity, polycystic ovary syndrome, type 2 diabetes mellitus etc., has prompted the need to assess insulin sensitivity in this age group. Even though insulin resistance plays an important role in disorders of glucose metabolism and other pathological conditions, both insulin sensitivity and insulin secretion should be determined for a comprehensive evaluation of glucose homeostasis disorders. Insulin sensitivity and secretion are intricately coupled with a delicate feedback mechanism governing their relationship. This article will delineate our paediatric experience with the clamp technique, the hyperinsulinaemic-euglycaemic clamp in assessing in vivo insulin sensitivity, and the hyperglycaemic clamp in assessing insulin secretion.

Usefulness of the addition of metformin to insulin in pediatric patients with type 1 diabetes mellitus

BACKGROUND

The aim of this study was to evaluate the effect of metformin in addition to insulin therapy in adolescents and young adults with type 1 diabetes mellitus.

METHODS

Nine patients, two males and seven females, aged 18.1 +/- 3.0 years, with type 1 diabetes mellitus were studied. They were relatively overweight with a body mass index (BMI) of 24.2 +/- 1.8 and had high levels of HbA1c at 9.5 +/- 1.2% despite high doses of insulin of 74.0 +/- 31.2 U/day. Metformin at the dose of 500-750 mg daily was administered to the patients in addition to insulin therapy for 1 year.

RESULTS

HbA1c, BMI and insulin dose were compared before 1 year without metformin therapy, at baseline, and at 3, 6 and 12 months during the use of metformin in addition to insulin therapy. HbA1c lowered (8.6 +/- 1.4**, 8.4 +/- 1.3**, 8.4 +/- 1.2*%), BMI was reduced (23.9 +/- 1.7*, 23.8 +/- 1.8, 23.5 +/- 1.8*), and insulin requirement decreased (69.8 +/- 29.7*, 68.7 +/- 29.8**, 67.3 +/- 29.1**U/d) significantly after the start of metformin therapy (*P < 0.05, **P < 0.01 vs at baseline). There were no adverse events, not even lactic acidosis, during the study period.

CONCLUSION

Metformin is safe and may represent a useful adjunct to the management of type 1 diabetes mellitus in adolescents and young adults who have poor glycemic control despite a large amount of insulin.

Insulin resistance in children and adolescents with type 1 diabetes mellitus: relation to obesity

BACKGROUND

Insulin resistance is well recognized both in type 1 diabetes mellitus (T1DM) and in obesity. Studies concerning the relation between insulin resistance and overweight in T1DM have not yet been carried out.

METHODS

Degree of overweight [standard deviation score-body mass index (SDS-BMI)] and daily insulin doses per weight (ID/kg), per body surface (ID/m2), and per ideal body weight (ID/IW) were recorded in 4124 children aged between 5 and 20 yr with a duration of T1DM of 4-5 yr and an adequate metabolic control [hemoglobin A1c (HbA1c) <8.0%]. SDS-BMI was compared between insulin-resistant (ID/kg > or = 1.0) and insulin-sensitive (ID/kg <1.0) children. The ID/kg, ID/m2, and ID/IW were compared between obese (SDS-BMI >1.9) and non-obese children. Multivariate linear regression analysis was conducted for the dependent variables ID/kg, ID/m2, and ID/IW, including age, gender, SDS-BMI, and HbA1c as independent variables.

RESULTS

The 882 insulin-resistant children did not differ significantly (p = 0.447) with respect to SDS-BMI (median +0.38) compared to the 3242 insulin-sensitive children (median SDS-BMI +0.42). The ID/kg was significantly (p = 0.031) lower in the obese children compared to the non-obese children (median 0.80 vs. 0.83), while ID/m2 (median 31.0 vs. 26.2) and ID/IW (median 1.17 vs. 0.85) were significantly (p < 0.001) increased in the obese children. In multivariate linear regression analysis, SDS-BMI was significantly (p < 0.001) associated with an increase in ID/m2 and ID/IW and a decrease in ID/kg.

CONCLUSIONS

T1DM children with insulin resistance based on ID/kg are not more overweight than insulin-sensitive children with T1DM. ID/m2 and ID/IW seem to reflect a better tool than ID/kg to describe the influence of overweight on insulin resistance in T1DM.

Altered growth in male peroxisome proliferator-activated receptor gamma (PPARgamma) heterozygous mice: involvement of PPARgamma in a negative feedback regulation of growth hormone action

The peroxisome proliferator-activated receptor gamma (PPARgamma) plays a major role in fat tissue development and physiology. Mutations in the gene encoding this receptor have been associated to disorders in lipid metabolism. A thorough investigation of mice in which one PPARgamma allele has been mutated reveals that male PPARgamma heterozygous (PPARgamma +/-) mice exhibit a reduced body size associated with decreased body weight, reflecting lean mass reduction. This phenotype is reproduced when treating the mice with a PPARgamma- specific antagonist. Monosodium glutamate treatment, which induces weight gain and alters body growth in wild-type mice, further aggravates the growth defect of PPARgamma +/- mice. The levels of circulating GH and that of its downstream effector, IGF-I, are not altered in mutant mice. However, the IGF-I mRNA level is decreased in white adipose tissue (WAT) of PPARgamma +/- mice and is not changed by acute administration of recombinant human GH, suggesting an altered GH action in the mutant animals. Importantly, expression of the gene encoding the suppressor of cytokine signaling-2, which is an essential negative regulator of GH signaling, is strongly increased in the WAT of PPARgamma +/- mice. Although the relationship between the altered GH signaling in WAT and reduced body size remains unclear, our results suggest a novel role of PPARgamma in GH signaling, which might contribute to the metabolic disorder affecting insulin signaling in PPARgamma mutant mice.

Body composition and bone mineral density in long-standing type 1 diabetes

OBJECTIVES

To study body composition and bone mineral density (BMD) in adult patients with long-standing type 1 diabetes mellitus.

RESEARCH DESIGN AND METHODS

In a population-based study, body composition and BMD were evaluated by dual energy X-ray absorptiometry in 38 patients with type 1 diabetes since childhood, compared with 38 age- and sex-matched controls. The mean age was 43 years (range 33-55 years) and the mean duration of diabetes was 33 years (range 28-37 years).

RESULTS

Besides a tendency to a reduced abdominal fat mass in diabetic males, no difference was observed in fat mass, muscle mass, or BMD between the groups. Significant correlations were found between insulin dosage and whole body fat mass in diabetic females and between serum cholesterol levels and abdominal fat mass in diabetic males.

CONCLUSION

Patients with long-standing type 1 diabetes with onset in childhood and adolescence seem to show only minor differences in body composition and no difference in BMD compared with closely matched healthy controls.

Potential Adjunctive Therapies in Adolescents with Type 1 Diabetes Mellitus

Appropriate insulin therapy is central to the management of all individuals with type 1 diabetes mellitus. The potential role of adjunctive therapy in type 1 diabetes is to improve insulin action, and facilitate the ability of all individuals with type 1 diabetes to achieve and maintain 'better' metabolic control. The landmark clinical trial in type 1 diabetes is the Diabetes Control and Complications Trial (DCCT). The DCCT showed that there is no threshold below which a reduction in glycemia would not provide further benefit against diabetes-related microvascular complications. This study in particular provides the rationale for attempting to achieve as near normoglycemia as possible. We review the use of recognized pharmacologic agents as potential insulin adjunctives in children and adolescents with type 1 diabetes. Adjunctive therapies can be grouped into the following categories based on their putative mechanism of action: enhancement of insulin action (e.g. the biguanides and thiazolidinediones), alteration of gastrointestinal nutrient delivery (e.g. acarbose and amylin), and other targets of action (e.g. pirenzepine and insulin-like growth factor-1 [IGF-1], which reduce growth hormone secretion, and glucagon-like peptide-1, which acts to stimulate insulin secretion). Many of these agents have been found to be effective in short-term studies with decreases in glycosylated hemoglobin of 0.5-1.0%, lowered postprandial blood glucose levels, and decreased daily insulin doses. Adverse effects such as poor gastrointestinal tolerability (metformin, acarbose) or potential acceleration of retinopathy (IGF-1) indicates the need for further studies of efficacy, safety, and patient selection before these adjunctive therapies can be widely recommended in type 1 diabetes.

Body composition in adolescent girls with type 1 diabetes

AIMS

To compare body composition in adolescent girls with Type 1 diabetes with healthy controls.

RESEARCH DESIGN AND METHODS

In this population-based study, body composition was examined, using dual-energy X-ray absorptiometry (DXA) and skinfold measurements, in 18 adolescent post-menarcheal females, 16-19 years of age, with Type 1 diabetes since childhood in comparison to age-matched healthy control subjects.

RESULTS

Body mass index was 2.7 kg/m2 higher in diabetic patients (26.3 +/- 2.6 vs. 23.6 +/- 3.8; P < 0.05). The overweight consisted almost entirely of increased fat mass, as evaluated by both skinfold measurements and DXA. Bone mineral density did not differ between the two groups. In diabetic females, the distribution of the fat mass was increased in the upper part of the body. The fat distribution, expressed as the abdominal-to-leg ratio, was significantly correlated to glycated haemoglobin (HbA1c) (r = 0.69; P < 0.005), daily dosage of insulin expressed per kilogram body weight (r = 0.78; P < 0.0005) and total cholesterol (r = 0.60; P < 0.001).

CONCLUSIONS

The observed overweight in adolescent females with Type 1 diabetes is explained by an increased fat mass. Abdominal fat accumulation was associated with poor glycaemic control, increased need for insulin and elevated blood lipids.

Metformin as an adjunct therapy in adolescents with type 1 diabetes and insulin resistance: a randomized controlled trial

OBJECTIVE

To evaluate whether, in adolescents with type 1 diabetes, the addition of metformin to insulin and standard diabetes management results in 1) higher insulin sensitivity and 2) lower HbA1c, fasting glucose, insulin dosage (units per kilogram per day) and BMI.

RESEARCH DESIGN AND METHODS

This was a randomized, placebo-controlled 3-month trial of metformin therapy in 27 adolescents with type 1 diabetes, high insulin dosage (>1 unit. kg(-1). day(-1)), and HbA1c >8%, with measurements of insulin sensitivity (by frequently sampled intravenous glucose tolerance test [FSIGT]), HbA1c, insulin dosage, and BMI at the onset and end of treatment.

RESULTS

At t = 0, HbA1c was 9.2 +/- 0.9%, insulin dosage was 1.2 +/- 0.2 units. kg(-1). day(-1), fasting glucose was 10.6 +/- 2.4 mmol/l, and BMI was 24.2 +/- 3.9 kg/m2 (means +/- SD), with no difference between the metformin and placebo groups. At the end of the study, HbA1c was 0.6% lower in the metformin group than in the placebo group (P < 0.05). This was achieved at lower daily insulin dosages (metformin group -0.14 +/- 0.1 vs. placebo group 0.02 +/- 0.2 units. kg(-1). day(-1); P < 0.05), with no significant change in BMI. Fasting glucose levels improved significantly in the metformin group (P < 0.05). Change in insulin sensitivity, measured by FSIGT, was not significantly different between the two groups at study end. Mild hypoglycemia occurred more frequently in the metformin-treated than in the placebo subjects (1.75 +/- 0.8 vs. 0.9 +/- 0.4 events. patient(-1). week(-1); P = 0.03). There were no differences in frequency of severe hypoglycemic episodes or gastrointestinal complaints between the two groups.

CONCLUSIONS

Metformin treatment lowered HbA1c and decreased insulin dosage with no weight gain in teens with type 1 diabetes in poor metabolic control. Changes in insulin sensitivity were not documented in this study using the FSIGT. Long-term studies will determine whether these improvements are sustained and whether certain subgroups accrue greater benefit from this therapy.

A mathematical model for pattern of change in beta-cell reserve and factors affecting residual reserve within the first 2 years of type 1 diabetes

The aim of this study was to investigate the effects of age, duration of diabetes, sex and ICA (Islet cell cytoplasmic antibody) on beta-cell reserves and to develop a model within the first 2 years of Type 1 diabetes. Beta-cell reserve is evaluated as fasting (FCp) and 1 mg i.v. glucagon stimulated C-peptide (SCp) levels in 58 Type 1 diabetics and in 12 normoglycemic subjects. Patients were divided into 3 groups according to duration of diabetes: Group I (2.5+/-0.3 weeks), Group II (13.4+/-1.2 months) and Group III (24.2+/-1.8 months). FCp/SCp level in nmol/l (mean+/-SE) were as follows. Group I: 0.21+/-0.02/0.38+/-0.04, Group II: 0.15+/-0.01/0.27+/-0.02, Group III: 0.07+/-0.01/0.11+/-0.02, CONTROL GROUP: 0.42+/-0.09/1.29+/-0.13. The scatter plots of C-peptide levels vs time in all the diabetic patients fitted in to a 4th-order polynomial regression (R: 0.96-0.98). Age was strongly correlated with FCp (rs: 0.46, p<0.05) and ICA positivity affected Cp-levels negatively (p>0.05). In conclusion, as the duration of diabetes increases, response time to glucagon prolongs and amplitude of it shortens. Duration of diabetes of less than 2 weeks, feminity, puberty and ICA positivity affect beta-cell reserve negatively, conversely, masculinity, post-puberty, older age and ICA negativity affect the reserve positively. The dynamics of C-peptide response to glucagon follow a mathematical model and Type 1 diabetes causes a decrease not only in the amplitude of the response but also in the duration of the response.

Pubertal alterations in growth and body composition. VI. Pubertal insulin resistance: relation to adiposity, body fat distribution and hormone release

OBJECTIVE

To investigate the independent influence of alterations in fat mass, body fat distribution and hormone release on pubertal increases in fasting serum insulin concentrations and on insulin resistance assessed by the homeostasis model (HOMA).

DESIGN AND SUBJECTS

Cross-sectional investigation of pre- (n=11, n=8), mid- (n=10, n=11), and late-pubertal (n=10, n=11) boys and girls with normal body weight and growth velocity.

MEASUREMENTS

Body composition (by a four-compartment model), abdominal fat distribution and mid-thigh interfascicular plus intermuscle (extramyocellular) fat (by magnetic resonance imaging), total body subcutaneous fat (by skinfolds), mean nocturnal growth hormone (GH) release and 06:00 h samples of serum insulin, sex steroids, leptin and insulin-like growth factor-I (IGF-I).

RESULTS

Pubertal insulin resistance was suggested by greater (P<0.001) fasting serum insulin concentrations in the late-pubertal than pre- and mid-pubertal groups while serum glucose concentrations were unchanged and greater (P<0.001) HOMA values in late-pubertal than pre- and mid-pubertal youth. From univariate correlation fat mass was most related to HOMA (r=0.59, P<0.001). Two hierarchical regression models were developed to predict HOMA. In one approach, subject differences in sex, pubertal maturation, height and weight were held constant by adding these variables as a block in the first step of the model (r(2)=0.36). Sequential addition of fat mass (FM) increased r(2) (r(2)((inc)remental)=0.08, r(2)=0.44, P<0.05) as did the subsequent addition of a block of fat distribution variables (extramyocellular fat, abdominal visceral fat, and sum of skinfolds; r(2)(inc)=0.11, r(2)=0.55, P<0.05). Sequential addition of a block of hormone variables (serum IGF-I and log((10)) leptin concentrations; r(2)(inc)=0.04, P>0.05) did not reliably improve r(2) beyond the physical characteristic and adiposity variables. In a second model, differences in sex and pubertal maturation were again held constant (r(2)=0.25), but body size differences were accounted for using percentage fat data. Sequential addition of percentage body fat (r(2)((inc)remental)=0.11, r(2)=0.36, P<0.05), then a block of fat distribution variables (percentage extramyocellular fat, percentage abdominal visceral fat, and percentage abdominal subcutaneous fat; r(2)(inc)=0.08, r(2)=0.44, P=0.058), and then a block of serum IGF-I and log((10)) leptin concentrations (r(2)(inc)=0.07, r(2)=0.51, P<0.05) increased r(2). Mean nocturnal GH release was not related to HOMA (r=-0.04, P=0.75) and therefore was not included in the hierarchical regression models.

CONCLUSION

Increases in insulin resistance at puberty were most related to FM. Accumulation of fat in the abdominal visceral, subcutaneous and muscular compartments may increase insulin resistance at puberty beyond that due to total body fat. Serum concentrations of leptin and IGF-I may further modulate HOMA beyond the effects of adiposity and fat distribution. However, the results are limited by the cross-sectional design and the use of HOMA rather than a criterion measure of insulin resistance.

Transition from multiple daily injections to continuous subcutaneous insulin infusion in type 1 diabetes mellitus

OBJECTIVE

To review our experience with insulin dosing during the conversion from multiple daily injections to continuous subcutaneous insulin infusion (CSII) for children and adolescents with type 1 diabetes mellitus.

STUDY DESIGN

The charts of 65 children who started CSII from January 1998 to April 2000 were reviewed. Data regarding insulin dose and hemoglobin A1c levels were collected from the prepump visit and first (at 1 to 2 months) and second (at 3 to 6 months) visits after being placed on pump therapy.

RESULTS

Pubertal patients had a decrease in total insulin dose taking CSII; prepubertal patients had little change (-18 +/- 3.5% vs -1.7 +/- 5%, P =.01). On CSII, the basal insulin dose comprised 40% to 45% of total insulin in both prepubertal and pubertal patients. Maximal basal rate in prepubertal patients occurred from 9 PM to 12 AM and in pubertal patients from 3 AM to 9 AM and from 9 PM to 12 AM.

CONCLUSION

Guidelines established for CSII dosing in adults do not necessarily apply to children. The total daily insulin dose needs to be decreased in pubertal patients but may remain unchanged in prepubertal patients. The basal rate comprises 40% to 45% of the total daily insulin dose, and the timing of maximum basal rates is likely to occur in the late evening hours in prepubertal children.

The short insulin tolerance test lacks validity in adolescents with Type 1 diabetes

AIMS

The short insulin tolerance test (SITT) has been found to be a simple and valid method for determining insulin sensitivity in healthy adults and patients with Type 2 diabetes. In this study we evaluated the reproducibility and validity of SITT in 16 adolescents with Type 1 diabetes.

METHODS

Thirteen patients underwent two SITT and eight patients were examined with both SITT and a euglycaemic hyperinsulinaemic clamp. At the SITT insulin sensitivity was measured from the slope of arterialized blood glucose concentrations determined for 16 min after an intravenous bolus injection of short-acting insulin, 0.1 U/kg body weight, and expressed as glucose disappearance rate (KITT).

RESULTS

There was a significant correlation between the insulin sensitivity estimations made at the two SITT (r = 0.73, P = 0.003). The reproducibility was low, however, with a coefficient of variation of 38.7%. KITT showed a strong inverse correlation to the fasting blood glucose concentration (r = -0.74, P < 0.0001). We found no correlation between insulin sensitivity measured by SITT and that measured by the euglycaemic clamp.

CONCLUSIONS

We conclude that the short insulin tolerance test cannot be used in adolescent patients with Type 1 diabetes for a simple estimation of insulin sensitivity.

Idiopathic Type 1 diabetes

The purpose of this article is to review the available pathophysiological and clinical studies of patients with idiopathic Type 1 diabetes. Idiopathic Type 1 diabetes is a common form of diabetes most commonly seen in obese African American individuals living in large urban areas. This type of diabetes usually presents with the typical signs and symptoms of Type 1 diabetes such as diabetic ketoacidosis but its subsequent clinical course often resembles Type 2 diabetes. The natural history and pathogenesis of idiopathic Type 1 diabetes is unknown because most of these studies on these patients were done shortly after diagnosis. For the most part, these patients have been treated as if they had Type 2 diabetes with diet and/or oral agents but recent studies suggest that patients have a very variable response to diet and oral agents. They seem to have better long-term glycemic control with the use of insulin therapy. Although the pathogenesis of this disease is unknown, it may be related to lipotoxicity, glucose toxicity or transcription factors involved in fuel metabolism.

Deteriorating diabetic control through adolescence-do the origins lie in childhood?

AIMS

To determine whether intra-individual measures of diabetes control deteriorated through adolescence and whether HbA1c in late childhood was predictive of HbA1c after adolescence.

METHODS

Retrospective analysis of sequential 3-6 monthly data including HbA1c, height, weight, and total daily insulin dosage in 118 patients with Type 1 diabetes aged between 8.00 and 17.99 years between 1983 and 1999.

RESULTS

In females mean body mass index (BMI) increased sharply during adolescence but there was no significant increase in males. The mean total daily dose of insulin/weight (TDDI/W) increased sharply for females through puberty. Males exhibited a constant rate of increase in mean TDDI/W from pre- to post-puberty. There was a constant increase in mean HbA1c for females, with an estimated increase from pre- to post-puberty of 0.92%. In males there was only a slight increase from pre- to peri-puberty and no change subsequently. Comparing pre-puberty (8-9.99 years) and post-puberty (15-17.99 years) in the total group, 47% of patients remained in the same mean HbA1c grouping, 37% had worsened control and 16% had improved control. Analysis of change in the absolute value of mean HbA1c showed that the majority of patients had mean HbA1c values that remained within +/- 1% (54%) or +/- 2% (82%) from pre- to post-puberty. A significant proportion showed significantly worsening control with only a minority showing improved metabolic control from pre- to post-puberty.

CONCLUSIONS

The likelihood of a significant improvement in HbA1c from late childhood to adolescence is remote, with the majority of patients having either constant or deteriorating metabolic control.

Sex differences in the growth of diabetic children

To investigate the effect of diabetes on the growth of children and to detect possible impairment of their final height, 58 Chinese subjects (22 boys; 36 girls) with childhood diabetes were studied longitudinally from diagnosis. Mean onset age at presentation was 8. 70 years. All patients were measured and weighed at diagnosis and every 3-4 months during the follow up period. Their height and weight measurements were converted to standard deviation scores (S.D. S.) using normal height and weight-for-height reference standards for Chinese children established in Hong Kong. The mean height S.D.S. for boys and girls at diagnosis were +0.76 and -0.07 (P=0.015). The mean final height S.D.S. for boys and girls were +0.14 and -0.57. The final heights of girls were significantly shorter than their target heights. At attainment of final height for diabetic girls, their mean weight-for-height S.D.S. was +0.76 indicating that they tended to become overweight. This study demonstrates the sex differences in the growth of diabetic children. Diabetic boys were tall for age at presentation but they achieved average final heights while diabetic girls attained below average adult stature and they tended to become obese.

Pubertal adolescent male-female differences in insulin sensitivity and glucose effectiveness determined by the one compartment minimal model

Most studies of insulin sensitivity in puberty have been cross-sectional and have not been able to longitudinally address changes that might occur. In addition, these studies were unable to separate out glucose's ability to stimulate its own disposal (glucose effectiveness, S(G)) from insulin sensitivity (S(I)) or to separate the hepatic and peripheral effects of insulin. To address these problems, we used the frequently sampled i.v. glucose tolerance test with [6,6]D2 glucose to study S(G)* and S(I)* in 24 children (Tanner stage 1-3) at 6-mo intervals over an 18-mo period. Mean overnight GH and fasting GH binding protein (GHBP), IGF-1, and leptin levels were also measured. S(G)* did not differ between the sexes or Tanner stages. S(I)* did not differ between Tanner stages for either sex and was higher in boys than in girls. Hepatic insulin resistance did not differ between sexes or Tanner stages. S(G)* was not related to any of the other variables measured. S(I)* was negatively related to BMI, GHBP, IGF1, and leptin. These results demonstrate that insulin sensitivity is greater in prepubertal and early pubertal boys than in girls and is primarily determined by body mass effects.

Increased prevalence of overweight in adolescent girls with type 1 diabetes mellitus

Height and weight were measured in young patients with type 1 diabetes up to the age of 22 y. We found no difference between birth length standard deviation scores (SDS), final height SDS and target height SDS. The study group of 89 diabetic boys and girls did not differ in final height from age- and sex-matched healthy controls. SDS for height at diagnosis, +0.17 +/- 1.10, exceeded that for final height, -0.06 +/- 0.97 (p = 0.037). Height SDS decreased between the ages of 11 and 18 (p < 0.01). In diabetic girls, but not boys, final height SDS was significantly related to mean HbA1c during puberty (r = -0.40; p = 0.025). Weight gain occurred from age of menarche in girls with type 1 diabetes. At the age of 18, diabetic girls were 6.5 kg heavier and had 2.7 kg/m2 higher body mass index (BMI) than control girls (p < 0.001). Diabetic boys were not heavier than control boys. There was a significant relationship between mean HbA1c during puberty and BMI at the age of 18 in diabetic girls (r = 0.47; p = 0.009). In diabetic females, body weight remained unchanged, HbA1c improved and the dose of insulin was significantly reduced between 18 and 22 y of age. The HbA1c improvement was most marked in patients with poor metabolic control. In conclusion, although mean final height was normal in young patients with type 1 diabetes, growth was increased before diagnosis and pubertal growth spurt was reduced. Adolescent overweight was overrepresented; it related to poor metabolic control in females with diabetes, but showed no further acceleration in early adulthood.

Eating disorders in adolescent girls with insulin-dependent diabetes mellitus: a population-based case-control study

In this study the prevalence of eating disorders in a population-based cohort of 89 female patients with type 1 diabetes, 14-18 y of age, was compared with that in age-matched healthy controls. Of all diabetic girls in the study area, 92% participated in the study. The majority were treated with multiple insulin injections and the mean HbA1c of the participants was 8.4%. On average, diabetic girls were 6.8 kg heavier than the controls. A two-stage design was used. The first consisted of a validated self-report questionnaire, the Eating Disorder Inventory (EDI). Girls who had high scores were then interviewed about eating habits and mental health using a semistructured interview, the BAB-T (Assessment of Anorexia-Bulimia - Teenager version). No cases of anorexia or bulimia nervosa were found, but 15 diabetic patients (16.9%) compared with 2 control girls (2.2%), p<0.01, had disturbed eating behaviour according to the questionnaire. In 6 of these 15 diabetic girls an eating disorder was confirmed at the interview, mainly binge eating and self-induced vomiting. None of the control girls showed an eating disorder. Overweight diabetic girls scored higher on EDI than non-overweight diabetic girls (chi2 = 4.9; p = 0.038). No relationships were found between EDI scores and metabolic control (HbA1c), dose of insulin, frequency of hypoglycaemia or diabetic ketoacidosis.

Sex differences in the adrenal catecholamine response to hypoglycemia in rats

We studied the influence of sex on the adrenal catecholamine response to acute insulin-induced hypoglycemia in Sprague-Dawley rats. Eight male and seven female adult rats were anesthetized with pentobarbital, and a microdialysis probe was placed in the left adrenal. Dialyzed epinephrine and norepinephrine levels were measured by high-performance liquid chromatography during a control period and for 1 hour after insulin administration. The blood glucose level was measured every 15 minutes. The same protocol was applied to 23 adult females at various stages of the estrus cycle. The pattern of blood glucose changes during insulin-induced hypoglycemia was similar in both sexes, but males exhibited a significantly greater increase in epinephrine than females (261% v 52%, P = .001) in the sex-comparison experiment. A similar trend was observed for norepinephrine (73% v 0%, P = .075). The adrenal response in females for both catecholamines was not significantly affected by the estrus cycle phase (P = .989 for epinephrine and P = .424 for norepinephrine). We conclude that sex influences the magnitude of the adrenal catecholamine counterregulatory response to hypoglycemia. Males had a significantly greater increase in epinephrine release than females exposed to the same pattern of hypoglycemia. Female responses to hypoglycemia were not influenced by estrus cyclicity.

Age governs gender-dependent islet cell autoreactivity and predicts the clinical course in childhood IDDM

Most IDDM patients temporarily restore some of their beta-cell function following the initiation of insulin therapy. The aim of this study was to analyse the influence of age, gender, metabolic state at diagnosis and presence of autoantibodies (GAD65 antibodies and ICA) on the duration of the clinical partial remission. In total, 149 consecutively diagnosed IDDM children, 0-16 y old (70F, 79M, mean age 9.5 y) were studied. Partial remission was arbitrarily defined as the period when the insulin dose was below 0.5 U/BW 24 h-1 and HbA1c below 7.5%, and occurred in 119/149 patients with a duration between 1 and 38 months. Cox's regression analysis showed that the factors significantly associated with the duration of remission were age, gender, interaction between age and gender, ICA and a high initial HbA1c, whereas GAD65Ab had no influence. Young boys had the shortest remission period, while adolescent boys had the longest, as compared to young and adolescent girls. The ICA-negative patients (n = 42) had a longer remission period (median 9.7 months) than the ICA-positive children (n = 107; 5.0 months; p = 0.0001), regardless of GAD65Ab status. We speculate that the relative insulin resistance, which is more pronounced in pubertal girls than in boys, may be associated with a more rapid increase of exogenous insulin requirement. These findings are important when evaluating the effect of islet cell autoreactivity on the clinical course of IDDM in children.

Growth in the diabetic child

Insulin has an important role in the GH:IGF-I axis, and its absence leads to major endocrine disturbances, particularly during puberty. Rapid growth in the prediabetic phase occurs and may be a risk factor. Final height reflects gender and the age of onset more than specific growth factors. The influence of hepatic insulin on IGF-I bioactivity has important implications in diabetic adolescents.