Jean M. Lawrence

Continuous glucose monitoring and intensive treatment of type 1 diabetes

BACKGROUND The value of continuous glucose monitoring in the management of type 1 diabetes mellitus has not been determined. METHODS In a multicenter clinical trial, we randomly assigned 322 adults and children who were already receiving intensive therapy for type 1 diabetes to a group with continuous glucose monitoring or to a control group performing home monitoring with a blood glucose meter. All the patients were stratified into three groups according to age and had a glycated hemoglobin level of 7.0 to 10.0%. The primary outcome was the change in the glycated hemoglobin level at 26 weeks. RESULTS The changes in glycated hemoglobin levels in the two study groups varied markedly according to age group (P=0.003), with a significant difference among patients 25 years of age or older that favored the continuous-monitoring group (mean difference in change, -0.53%; 95% confidence interval [CI], -0.71 to -0.35; P<0.001). The between-group difference was not significant among those who were 15 to 24 years of age (mean difference, 0.08; 95% CI, -0.17 to 0.33; P=0.52) or among those who were 8 to 14 years of age (mean difference, -0.13; 95% CI, -0.38 to 0.11; P=0.29). Secondary glycated hemoglobin outcomes were better in the continuous-monitoring group than in the control group among the oldest and youngest patients but not among those who were 15 to 24 years of age. The use of continuous glucose monitoring averaged 6.0 or more days per week for 83% of patients 25 years of age or older, 30% of those 15 to 24 years of age, and 50% of those 8 to 14 years of age. The rate of severe hypoglycemia was low and did not differ between the two study groups; however, the trial was not powered to detect such a difference. CONCLUSIONS Continuous glucose monitoring can be associated with improved glycemic control in adults with type 1 diabetes. Further work is needed to identify barriers to effectiveness of continuous monitoring in children and adolescents. (ClinicalTrials.gov number, NCT00406133.)

The Burden of Diabetes Mellitus Among US Youth: Prevalence Estimates From the SEARCH for Diabetes in Youth Study

OBJECTIVE. Our goal was to estimate the prevalence of diabetes mellitus in youth <20 years of age in 2001 in the United States, according to age, gender, race/ethnicity, and diabetes type. METHODS. The SEARCH for Diabetes in Youth Study is a 6-center observational study conducting population-based ascertainment of physician-diagnosed diabetes in youth. Census-based denominators for 4 geographically based centers and enrollment data for 2 health plan-based centers were used to calculate prevalence. Age-, gender-, and racial/ethnic group-specific prevalence rates were multiplied by US population counts to estimate the total number of US youth with diabetes. RESULTS. We identified 6379 US youth with diabetes in 2001, in a population of ∼3.5 million. Crude prevalence was estimated as 1.82 cases per 1000 youth, being much lower for youth 0 to 9 years of age (0.79 cases per 1000 youth) than for those 10 to 19 years of age (2.80 cases per 1000 youth). Non-Hispanic white youth had the highest prevalence (1.06 cases per 1000 youth) in the younger group. Among 10- to 19-year-old youth, black youth (3.22 cases per 1000 youth) and non-Hispanic white youth (3.18 cases per 1000 youth) had the highest rates, followed by American Indian youth (2.28 cases per 1000 youth), Hispanic youth (2.18 cases per 1000 youth), and Asian/Pacific Islander youth (1.34 cases per 1000 youth). Among younger children, type 1 diabetes accounted for ≥80% of diabetes; among older youth, the proportion of type 2 diabetes ranged from 6% (0.19 cases per 1000 youth for non-Hispanic white youth) to 76% (1.74 cases per 1000 youth for American Indian youth). We estimated that 154369 youth had physician-diagnosed diabetes in 2001 in the United States. CONCLUSIONS. The overall prevalence estimate for diabetes in children and adolescents was ∼0.18%. Type 2 diabetes was found in all racial/ethnic groups but generally was less common than type 1, except in American Indian youth.

Epidemiology of Type 1 Diabetes

This article describes the epidemiology of type 1 diabetes mellitus (T1D) around the world and across the lifespan. Epidemiologic patterns of T1D by demographic, geographic, biologic, cultural, and other factors in populations are presented to gain insight about the causes, natural history, risks, and complications of T1D. Data from large epidemiologic studies worldwide indicate that the incidence of T1D has been increasing by 2% to 5% worldwide and that the prevalence of T1D is approximately 1 in 300 in the United States by 18 years of age. Research on risk factors for T1D is an active area of research to identify genetic and environmental triggers that could potentially be targeted for intervention. Although significant advances have been made in the clinical care of T1D with resultant improvements in quality of life and clinical outcomes, much more needs to be done to improve care of, and ultimately find a cure for, T1D. Epidemiologic studies have an important ongoing role to investigate the complex causes, clinical care, prevention, and cure of T1D.

The SEARCH for Diabetes in Youth study: rationale, findings, and future directions.

The SEARCH for Diabetes in Youth (SEARCH) study was initiated in 2000, with funding from the Centers for Disease Control and Prevention and support from the National Institute of Diabetes and Digestive and Kidney Diseases, to address major knowledge gaps in the understanding of childhood diabetes. SEARCH is being conducted at five sites across the U.S. and represents the largest, most diverse study of diabetes among U.S. youth. An active registry of youth diagnosed with diabetes at age <20 years allows the assessment of prevalence (in 2001 and 2009), annual incidence (since 2002), and trends by age, race/ethnicity, sex, and diabetes type. Prevalence increased significantly from 2001 to 2009 for both type 1 and type 2 diabetes in most age, sex, and race/ethnic groups. SEARCH has also established a longitudinal cohort to assess the natural history and risk factors for acute and chronic diabetes-related complications as well as the quality of care and quality of life of persons with diabetes from diagnosis into young adulthood. Many youth with diabetes, particularly those from low-resourced racial/ethnic minority populations, are not meeting recommended guidelines for diabetes care. Markers of micro- and macrovascular complications are evident in youth with either diabetes type, highlighting the seriousness of diabetes in this contemporary cohort. This review summarizes the study methods, describes key registry and cohort findings and their clinical and public health implications, and discusses future directions.

The effect of continuous glucose monitoring in well-controlled type 1 diabetes.

OBJECTIVE The potential benefits of continuous glucose monitoring (CGM) in the management of adults and children with well-controlled type 1 diabetes have not been examined. RESEARCH DESIGN AND METHODS A total of 129 adults and children with intensively treated type 1 diabetes (age range 8–69 years) and A1C <7.0% were randomly assigned to either continuous or standard glucose monitoring for 26 weeks. The main study outcomes were time with glucose level ≤70 mg/dl, A1C level, and severe hypoglycemic events. RESULTS At 26 weeks, biochemical hypoglycemia (≤70 mg/dl) was less frequent in the CGM group than in the control group (median 54 vs. 91 min/day), but the difference was not statistically significant (P = 0.16). Median time with a glucose level ≤60 mg/dl was 18 versus 35 min/day, respectively (P = 0.05). Time out of range (≤70 or >180 mg/dl) was significantly lower in the CGM group than in the control group (377 vs. 491 min/day, P = 0.003). There was a significant treatment group difference favoring the CGM group in mean A1C at 26 weeks adjusted for baseline (P < 0.001). One or more severe hypoglycemic events occurred in 10 and 11% of the two groups, respectively (P = 1.0). Four outcome measures combining A1C and hypoglycemia data favored the CGM group in comparison with the control group (P < 0.001, 0.007, 0.005, and 0.003). CONCLUSIONS Most outcomes, including those combining A1C and hypoglycemia, favored the CGM group. The weight of evidence suggests that CGM is beneficial for individuals with type 1 diabetes who have already achieved excellent control with A1C <7.0%.

Parity, Mode of Delivery, and Pelvic Floor Disorders

OBJECTIVE: This study aimed to assess the associations between parity, mode of delivery, and pelvic floor disorders. METHODS: The prevalence of pelvic organ prolapse, stress urinary incontinence, overactive bladder, and anal incontinence was assessed in a random sample of women aged 25–84 years by using the validated Epidemiology of Prolapse and Incontinence Questionnaire. Women were categorized as nulliparous, vaginally parous, or only delivered by cesarean. Adjusted odds ratios and 95% confidence intervals (CIs) for each disorder were calculated with logistic regression, controlling for age, body mass index, and parity. RESULTS: In the 4,458 respondents the prevalence of each disorder was as follows: 7% prolapse, 15% stress urinary incontinence, 13% overactive bladder, 25% anal incontinence, and 37% for any one or more pelvic floor disorders. There were no significant differences in the prevalence of disorders between the cesarean delivery and nulliparous groups. The adjusted odds of each disorder increased with vaginal parity compared with cesarean delivery: prolapse = 1.82 (95% CI 1.04–3.19), stress urinary incontinence = 1.81 (95% CI 1.25–2.61), overactive bladder = 1.53 (95% CI 1.02–2.29), anal incontinence = 1.72 (95% CI 1.27–2.35), and any one or more pelvic floor disorders = 1.85 (95% CI 1.42–2.41). Number-needed-to-treat analysis revealed that 7 women would have to deliver only by cesarean delivery to prevent one woman from having a pelvic floor disorder. CONCLUSION: The risk of pelvic floor disorders is independently associated with vaginal delivery but not with parity alone. Cesarean delivery has a protective effect, similar to nulliparity, on the development of pelvic floor disorders when compared with vaginal delivery. LEVEL OF EVIDENCE: II-2

Trends in serum folate after food fortification

From 1994 to 1998, median serum folate values in clinical specimens increased from 12.6 to 18.7 microg/L. The percentage of low values decreased. Food fortification with folic acid is a likely explanation.

Prevalence and co-occurrence of pelvic floor disorders in community-dwelling women.

OBJECTIVE: To assess the effect of age on prevalence of pelvic floor disorders and report the co-occurrence of these conditions in community-dwelling women. METHODS: Stress urinary incontinence (SUI), overactive bladder (OAB), pelvic organ prolapse (POP), and anal incontinence were assessed using a validated questionnaire among 25- to 84-year-old women. Women screened positive for each disorder based on reported symptoms and their degree of bother. Covariates were assessed through self-report. Prevalence of each disorder was compared across four 15-year age groups using &khgr;2 tests. Multiple logistic regression was used to adjust for confounders. RESULTS: Among 4,103 women (mean age 56.5±15.8 years), the prevalence of SUI was 15%, OAB 13%, POP 6%, anal incontinence 25%, and 37% for any one or more disorder. Although the unadjusted prevalence of SUI, OAB, and anal incontinence increased with increasing age category, age was no longer significantly associated with the prevalence of any condition in most categories after adjustment for confounders, including obesity, birth history, menopause, and hormones. Co-occurrence of the disorders was high; roughly 80% of women with SUI or OAB, 69% with POP, and 48% with anal incontinence reported at least one other disorder. CONCLUSION: Although the prevalence of pelvic floor disorders in a community-dwelling population is high, age was not a significant contributor after adjustment for confounders. The high co-occurrence of pelvic floor disorders suggests that physicians seeing women seeking care for one condition should inquire about symptoms of other disorders. LEVEL OF EVIDENCE: II

Projections of type 1 and type 2 diabetes burden in the U.S. population aged <20 years through 2050: dynamic modeling of incidence, mortality, and population growth.

OBJECTIVE To forecast the number of U.S. individuals aged <20 years with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) through 2050, accounting for changing demography and diabetes incidence. RESEARCH DESIGN AND METHODS We used Markov modeling framework to generate yearly forecasts of the number of individuals in each of three states (diabetes, no diabetes, and death). We used 2001 prevalence and 2002 incidence of T1DM and T2DM from the SEARCH for Diabetes in Youth study and U.S. Census Bureau population demographic projections. Two scenarios were considered for T1DM and T2DM incidence: 1) constant incidence over time; 2) for T1DM yearly percentage increases of 3.5, 2.2, 1.8, and 2.1% by age-groups 0–4 years, 5–9 years, 10–14 years, and 15–19 years, respectively, and for T2DM a yearly 2.3% increase across all ages. RESULTS Under scenario 1, the projected number of youth with T1DM rises from 166,018 to 203,382 and with T2DM from 20,203 to 30,111, respectively, in 2010 and 2050. Under scenario 2, the number of youth with T1DM nearly triples from 179,388 in 2010 to 587,488 in 2050 (prevalence 2.13/1,000 and 5.20/1,000 [+144% increase]), with the greatest increase in youth of minority racial/ethnic groups. The number of youth with T2DM almost quadruples from 22,820 in 2010 to 84,131 in 2050; prevalence increases from 0.27/1,000 to 0.75/1,000 (+178% increase). CONCLUSIONS A linear increase in diabetes incidence could result in a substantial increase in the number of youth with T1DM and T2DM over the next 40 years, especially those of minority race/ethnicity.

Prevalence of overweight and obesity in youth with diabetes in USA: the SEARCH for Diabetes in Youth study.

Liu LL, Lawrence JM, Davis C, Liese AD, Pettitt DJ, Pihoker C, Dabelea D, Hamman R, Waitzfelder B, Kahn HS. Prevalence of overweight and obesity in youth with diabetes in USA: the SEARCH for Diabetes in Youth Study.