Reliability of the 30-minute ACTH test in assessing hypothalamic-pituitary-adrenal function.

An insulin hypoglycemia test and a 30-min ACTH test were performed in 90 patients with proved or suspected hypothalamic-pituitary-adrenal hypofunction and in 10 normal subjects. The peak plasma cortisol concentration during hypoglycemia and the cortisol concentration at 30 min after injection of 250 micrograms corticotropin 1-24 were compared. A very close correlation (r = 0.92) was found between the the two concentrations, with no major discrepancy in any case. It is concluded that the short ACTH test accurately reflects the integrated hypothalamic-pituitary-adrenal function, as assessed by the insulin hypoglycemia test.     

Combined seropositivity for H. pylori and C. pneumoniae is associated with age, obesity and social factors

BACKGROUND: Manifestations of cardiovascular disease (CVD) have been associated with chronic infection by Helicobacter pylori and Chlamydia pneumoniae both in cross-sectional and in prospective follow-up cohort studies. This association may be partly due to an increase in metabolic risk factors for CVD, secondary to low-grade inflammation caused by infections. OBJECTIVE: To investigate for subjects classified according to serology titres for infection with C. pneumoniae and H. pylori associations between seropositivity and the degree of obesity and fasting insulin levels, as well as social factors. METHODS: Using methods based on those in earlier investigations of hypertensive patients in the Dalby primary-health-care district, southern Sweden, we investigated frozen samples from serum of 310 middle-aged treated hypertensives and 288 age-matched and sex-matched normotensive controls from a defined population. The baseline examination included the measurement of weight, height and blood pressure as a mean of two office readings with the subject supine. The body mass index (BMI) was calculated as kg/m2. Fasting blood samples were drawn for measurements of levels of serum lipids, blood glucose, plasma insulin and serum lipids, including total cholesterol and triglycerides. The serology titres for H. pylori were determined by an enzyme-linked immunosorbent assay. The titres for C. pneumoniae were determined by a micro-immunofluorescence method. Self-reported factors concerning social and lifestyle backgrounds were recorded. RESULTS: The group (n = 245) of subjects with combined positive serology for H. pylori and C. pneumoniae differed from the group without any positive serology (n = 57) in age (61.6 versus 57.4 years, P < 0.05) and BMI (27.3 versus 25.8 kg/m2, P < 0.05). The seropositive group also differed in terms of fasting levels of insulin (12.7 versus 11.6 pmol/l, P < 0.05), but this difference did not remain significant after adjustment for age and BMI. We detected no intergroup difference in blood pressure and levels of glucose and lipids. Members of the group with combined seropositivity reported having a lower social-class position (educational level) than that of members of the seronegative group. CONCLUSION: Subjects with combined positive serology for H. pylori and C. pneumoniae are characterized by greater age, lower social class and higher BMI, as well as higher fasting levels of insulin than those of seronegative subjects. Obesity might be a marker not only for lower social class but also for greater than normal susceptibility to such infections.     

Does blood pressure differ between users and non-users of hormone replacement therapy? The Women's Health In the Lund Area (WHILA) Study

OBJECTIVE: To examine whether blood pressure over 24 h differed between postmenopausal women receiving and not receiving hormone replacement therapy. METHODS: One group of hormone replacement postmenopausal women (n = 32) and one group of non-hormone replacement (n = 32) postmenopausal women underwent non-invasive 24-h ambulatory blood pressure monitoring. They were randomly selected among the 2000 firstly screened women in an ongoing project in Lund, Sweden. The study was designed to detect a difference of 5 mmHg in diastolic blood pressure over 24 h with a power of 80% and 5% significance (two-tailed test). RESULTS: The hormone replacement women had a mean (SD) office blood pressure of 128/76 (12/8) mmHg and the non-hormone replacement 126/78 (16/8) mmHg. Mean ambulatory blood pressure over 24 h, day and night, in the hormone replacement group was 121/72 (11/7), 126/76 (12/8), 111/64 (11/7) mmHg. The corresponding values in the non-hormone replacement group were 118/72 (12/7), 124/77 (12/7), and 107/64 (13/7) (p > 0.40 for diastolic blood pressure and p > 0.20 for systolic blood pressure). Mean heart rate over 24 h was 71 (7) and 73 (8) beats/min in the hormone and non-hormone replacement groups, respectively. CONCLUSION: There was no difference in blood pressure or heart rate between the hormone replacement and non-hormone replacement postmenopausal women, either over 24 h or during the day or night. Hormone replacement in postmenopausal women seems not to have an influence on blood pressure, but of course we are aware that this is a cross-sectional study, which has its limitations.     

Gastrin in pituitary tumours

Twelve of 87 pituitary adenomas from patients with acromegaly, Cushing's syndrome. Nelson's syndrome, hyperprolactinaemia and without symptoms of hormone hypersecretion contained gastrin in concentrations from 0.5 to 166 pmol/g. Only ACTH-producing tumours contained gastrin, which occurred in forms smaller than those present in the normal adenohypophysis. The results indicate that corticotropic tumours may synthesize gastrin in moderate amounts.     

The ratio between serum levels of insulin-like growth factor (IGF)-I and the IGF binding proteins (IGFBP-1, 2 and 3) decreases with age in healthy adults and is increased in acromegalic patients

OBJECTIVE Several in-vitro studies have suggested that the biological actions of IGF-I can be modified by the presence of specific IGF binding proteins. In man, the 24-hour serum levels of IGF-I and IGFBP-3 remain constant, but short-term changes in the IGF-l/IGFBP-3 ratio have been described following GH administration. Serum levels of IGF-I and IGFBP-3 decrease with age in normal adults and are elevated In active acromegaly due to excessive GH secretion. However, the Individual ratios between serum levels of IGF-I and IGFBP-3 in acromegalic and healthy adults have not been described previously. METHODS AND MATERIALS We studied this ratio In 198 healthy adults and In 56 acromegalic patients, grouped according to their serum GH levels (group I GH < 2mLU/l II GH 2–10mLU/l; III GH > 10mLU/l). In all subjects a single blood sample was drawn for IGF-I, IGF-II, IGFBP-1, IGFBP-2, IGFBP-3 and GH measurements by specific RIAs. In 38 of the patients a 24-hour urinary collection was performed for GH determination. RESULTS In healthy adults serum levels of IGF-I and IGFBP-3 decreased with Increasing age (r =?0.52 and r=?0.34, respectively, P< 0.0001). In addition, the molar IGF-l/IGFBP-3 ratio declined with increasing age (r =?0.44, P – 0.0001). In patients with acromegaly and high serum GH levels (group III), circulating IGF-I was increased 7–97 standard deviations (SDS) and IGFBP-3 was increased 4.20 SOS (P < 0.0001). Serum levels of IGF-II were normal in all three groups (588 ± 240μ/l) whereas IGFBP-1 and IGFBP-2 levels were low and IGFBP-2 levels decreased significantly with increasing serum GH levels (P < 0.0001). The molar IGF-l/IGFBP-3 ratio in the acromegalic patients was significantly higher than in the controls (P < 0.0001) and correlated significantly with urinary GH excretion (r = 0.67, P < 0.0001) as well as with serum GH levels (r = 0.73, P < 0.0001). CONCLUSION We demonstrated a decreasing molar IGF-l/IGFBP-3 ratio with increasing age in healthy adults and an increased ratio between serum IGF-I and IGFBP-3 levels in acromegalic patients. As IGF-II is normal and IGFBP-1 and IGFBP-2 are inversely correlated to the serum GH levels In the acromegalic patients, we speculate that the molar ratio between IGF-I and IGFBP-3 reflects free (biologically active) IGF-I and Is dependent on GH levels.     

Longitudinal prediction of falls and near falls frequencies in Parkinson’s disease: a prospective cohort study

Journal of Neurology - Several prediction models for falls/near falls in Parkinson’s disease (PD) have been proposed. However, longitudinal predictors of frequency of falls/near falls are...     

Low total haemoglobin mass, blood volume and aerobic capacity in men with type 1 diabetes

Blood O₂ carrying capacity affects aerobic capacity (VO_2max). Patients with type 1 diabetes have a risk for anaemia along with renal impairment, and they often have low VO_2max. We investigated whether total haemoglobin mass (tHb-mass) and blood volume (BV) differ in men with type 1 diabetes (T1D, n = 12) presently without complications and in healthy men (CON, n = 23) (age-, anthropometry-, physical activity-matched), to seek an explanation for low VO_2max. We determined tHb-mass, BV, haemoglobin concentration ([Hb]), and VO_2max in T1D and CON. With similar (mean ± SD) [Hb] (144 vs. 145 g l^?1), T1D had lower tHb-mass (10.1 ± 1.4 vs. 11.0 ± 1.1 g kg^?1, P < 0.05), BV (76.8 ± 9.5 vs. 83.5 ± 8.3 ml kg^?1, P < 0.05) and VO_2max (35.4 ± 4.8 vs. 44.9 ± 7.5 ml kg^?1 min^?1, P < 0.001) than CON. VO_2max correlated with tHb-mass and BV both in T1D (r = 0.71, P < 0.01 and 0.67, P < 0.05, respectively) and CON (r = 0.54, P < 0.01 and 0.66, P < 0.001, respectively), but not with [Hb]. Linear regression slopes were shallower in T1D than CON both between VO_2max and tHb-mass (2.4 and 3.6 ml kg^?1 min^?1 vs. g kg^?1, respectively) and VO_2max and BV (0.3 and 0.6 ml kg^?1 min^?1 vs. g kg^?1, respectively), indicating that T1D were unable to reach similar VO_2max than CON at a given tHb-mass and BV. In conclusion, low tHb-mass and BV partly explained low VO_2max in T1D and may provide early and more sensitive markers of blood O₂ carrying capacity than [Hb] alone.