Prevalence of detectable C-Peptide according to age at diagnosis and duration of type 1 diabetes.

OBJECTIVE: It is generally accepted that complete ß-cell destruction eventually occurs in individuals with type 1 diabetes, which has implications for treatment approaches and insurance coverage. The frequency of residual insulin secretion in a large cohort of individuals at varying ages of diagnosis and type 1 diabetes duration is unknown. RESEARCH DESIGN AND METHODS: The frequency of residual insulin secretion was determined by measurement of nonfasting serum C-peptide concentration in 919 individuals with type 1 diabetes according to prespecified groups based on age at diagnosis and duration of disease (from 3 to 81 years' duration). Stimulated C-peptide was measured in those with detectable nonfasting values and a group of those with undetectable values as control. RESULTS: The overall frequency of detectable nonfasting C-peptide was 29%, decreasing with time from diagnosis regardless of age at diagnosis. In all duration groups, the frequency of C-peptide was higher with diagnosis age >18 years compared with ≤18 years. Nineteen percent of those with undetectable nonfasting C-peptide were C-peptide positive upon stimulation testing. CONCLUSIONS: The American Diabetes Association's definition of type 1 diabetes as "usually leading to absolute insulin deficiency" results in clinicians often considering the presence of residual insulin secretion as unexpected in this population. However, our data suggest that residual secretion is present in almost one out of three individuals 3 or more years from type 1 diabetes diagnosis. The frequency of residual C-peptide decreases with time from diagnosis regardless of age at diagnosis, yet at all durations of disease, diagnosis during adulthood is associated with greater frequency and higher values of C-peptide.

Patterns of colonization with Ureaplasma urealyticum during neonatal intensive care unit hospitalizations of very low birth weight infants and the development of chronic lung disease.

BACKGROUND: Ureaplasma urealyticum and its association with chronic lung disease (CLD) of prematurity has remained a controversial topic. To readdress this question, we performed a longitudinal study using culture and polymerase chain reaction to detect U urealyticum in the respiratory tract of very low birthweight infants throughout their neonatal intensive care unit hospitalizations. METHODS: We screened 125 infants weighing <1500 g and/or <32 weeks' gestational age over a 12-month period, collecting endotracheal, nasopharyngeal, and throat specimens on days of age 1, 3, 7, and weekly thereafter. CLD was defined as dependency on supplemental oxygen at 28 days and at 36 weeks' postconceptional age. RESULTS: Forty infants (32%) had 1 or more positive specimens by culture or polymerase chain reaction. We identified 3 patterns of U urealyticum colonization: persistently positive (n = 18), early transient (n = 14), and late acquisition (n = 8). We compared the rates of CLD in each of the 3 colonized groups with the rate of CLD in the noncolonized group. We found a significantly higher rate of CLD at 28 days of age (odds ratio: 8.7; 95% confidence interval: 3.3, 23) and at 36 weeks' postconception (odds ratio: 38.5, 95% confidence interval: 4.0, 374) only for infants with persistently positive colonization. CONCLUSIONS: This study demonstrates that the risk of developing CLD varies with the pattern of U urealyticum colonization. Only the persistently positive colonization pattern, which accounted for 45% of the U urealyticum-positive infants, was associated with a significantly increased risk of development of CLD.