Biomedical subjects

D Kraenzle

Publications and source records attributed to D Kraenzle.

5 recordsLinked to original sources

PubMed1996

Relationship of age and calcitonin gene-related peptide to postprandial hypotension.

Falls following a meal occur commonly in older persons. These falls have been related to a decrease in postprandial blood pressure due to carbohydrates in the meal. The mechanism by which this occurs is not known. In this study, we examined the possible role of a vasodilatory peptide, calcitonin gene-related peptide (CGRP), which is released following carbohydrate loading in the pathophysiology of postprandial hypotension. Levels were assessed in 29 community-dwelling individuals aged 20-83 years during an oral glucose tolerance test, and heart rate and blood pressure were measured. Five subjects exhibited a postprandial reduction in systolic blood pressure (SBP) greater than 15 mmHg (mean reduction -30 +/- 4 mmHg). Four were aged over 60 (40% of the individuals in that group) and one was middle aged (11%). One individual in the older group was temporarily symptomatic, complaining of light-headedness. Linear regression analysis showed a significant association between the changes in CGRP and in blood pressure: SBP (r = 0.39, P = 0.037), and mean blood pressure (MBP) (r = 0.356, P = 0.06) in the oldest group. Individuals in this group with a greater than 15 mmHg drop in blood pressure, exhibited significantly greater changes in CGRP (SBP: P = 0.001, diastolic blood pressure (DBP): P = 0.05, MBP: P = 0.006). This association of log CGRP delta and BP change was not present in young or middle aged individuals. Thus, increases in CGRP levels were associated with blood pressure reduction, with older individuals more susceptible to these changes than younger individuals. CGRP may play a role in the pathogenesis of postprandial hypotension.

Adult↗

PubMed1996

Age-related changes in amylin secretion.

Amylin (islet amyloid polypeptide) is a recently identified pancreatic peptide. It has been shown to affect glucose metabolism both in vitro and in vivo. A cross sectional analysis of the effects of age on amylin secretion following a 75 g glucose tolerance test in a young (20-40 years), middle aged (41-60 years) and older (61-90 years) group was performed. Thirty lean (BMI less than 25) non-diabetic individuals were studied. Amylin secretion exhibited a U-shaped curve with greater secretion in young and old subjects than in middle aged persons. Baseline levels were 7.2 +/- 1, 4.7 +/- 1, and 5.3 +/- 0.75 pM respectively, at 60 min 9.5 +/- 0.9 (y), 5.5 +/- 1 (m), 8.6 +/- 1 (o) pM; and at 120 min 10.3 +/- 2 (y), 4.4 +/- 0.5 (m), 10.9 +/- 1.5 (o) pM. Amylin production (area under the curve) was 1102 +/- 131, 619.5 +/- 79 and 1043 +/- 120 pM per min respectively (P < 0.05). Amylin secretion was similar in both sexes. Variability in the insulin to amylin ratio for each of the age groups at different time points following a glucose load was found, suggesting that insulin and amylin are not co-secreted in a fixed ratio. A significant association was found between both maximum amylin and rise in amylin (delta) and a glucose greater than 120 mg/dl at 2 h. (P < 0.001, P < 0.001). This correlation of glucose and amylin may be interpreted as suggestive of a counterregulatory role for amylin. However, aging is also associated with changes in glucose metabolism and amylin may merely be acting as a marker of impaired glucose metabolism.

Adult↗

PubMed1994

Causes of weight loss in a community nursing home.

OBJECTIVE: To determine the causes of weight loss in nursing home residents. DESIGN: Retrospective chart review of all weights over the previous 6 months and an in-depth examination of all residents who lost 5 or more pounds over that period. SETTING: A for-profit community nursing home in an urban area. SUBJECTS: All residents who had been in the nursing home for 3 or more months. Their mean age was 80.1 years, and 89% were female. RESULTS: Weight loss of 5 pounds or more occurred in 19% of subjects. Only 15% of subjects had lost 5% of body weight, and 4% had lost more than 10% of their body weight. Depression accounted for 36% of the weight loss. Other causes of anorexia included medications, psychotropic drug reduction, swallowing disorders, paranoia, dementia with apraxia, gallstones, and obsessive-compulsive disorder. Increased energy utilization as a cause of weight loss was seen in two residents who wandered incessantly, one with tardive dyskinesia and one with chronic obstructive pulmonary disease. Dehydration was the cause of weight loss in two residents, and one resident had international weight loss for obesity. Cancer was the cause of weight loss in two residents. Four of 30 residents had more than one cause of weight loss. One of 25 tube-fed residents displayed weight loss. CONCLUSIONS: A single cause of weight loss can be identified in most nursing home residents. Depression is the most common cause of weight loss. Psychotropic drug reduction may cause weight loss. The majority of causes of weight loss in a community nursing home are potentially treatable.

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PubMed1993

Effects of testosterone replacement therapy in old hypogonadal males: a preliminary study.

OBJECTIVE: To examine the effects of testosterone administration to older hypogonadal males (bioavailable testosterone less than 70 ng/dL). DESIGN: Alternate-case controlled trial. SETTING: St. Louis University. PATIENTS: Eight males (mean age 77.6 +/- 2.3 years) who received testosterone and six males (mean age 76 +/- 2.3 years) who served as controls. Selected from alumni of the SHEP trial and attendees at the St. Louis University Impotence Clinic. INTERVENTIONS: Testosterone enanthate (200 mg/mL) was administered intramuscularly to the treatment group every 2 weeks for 3 months. MEASUREMENTS: Serum testosterone, bioavailable testosterone and estradiol, weight, % body fat, right hand muscle strength, balance, cholesterol, HDL-cholesterol, hematocrit, BUN, creatinine, albumin, calcium, PTH, 25(OH) vitamin D, 1,25(OH)2 vitamin D, osteocalcin, prostate-specific antigen, and fructosamine. RESULTS: Males who received testosterone had a significant increase in testosterone and bioavailable testosterone concentration, hematocrit, right hand muscle strength and osteocalcin concentration. They had a decrease in cholesterol (without a change in HDL-cholesterol) levels and decreased BUN/Creatinine ratios. CONCLUSION: These preliminary findings support the need for long term studies of testosterone therapy in older hypogonadal males.

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PubMed1993

A preliminary report of vitamin D and calcium metabolism in older African Americans.

OBJECTIVE: To determine normal serum bone-related biochemical variables in older African-Americans. DESIGN: A convenience sample of older African-Americans who had a health screening and blood testing for calciotropic hormones was compared with white Americans who were recruited at the end of the Systolic Hypertension in the Elderly Program (SHEP) study and were not on a thiazide diuretic. SETTING: Community-dwelling African-Americans who participated in SHEP or who attended one of two mass health screenings. PARTICIPANTS: Thirty-two African-Americans aged 68-93 years and 43 white Americans aged 70-89 years. MEASUREMENTS: Twenty-five hydroxyvitamin D (25OHD), parathyroid hormone, osteocalcin, and calcitonin. RESULTS: Serum 25OHD levels in 38% of the African-American men and 38% of African-American women were less than 8 ng/mL compared with 22% of Caucasian men and 40% of Caucasian women. Serum parathyroid hormone (PTH) was above the normal range in 25% of men and 33% of women of African-American descent and 14% of Caucasian men and 30% of Caucasian women. Serum 25OHD was lower (P < 0.05) in individuals with a previous history of fracture. Serum albumin (P < 0.05), calcitonin (P < 0.05), and osteocalcin (P < 0.05), but not 25OHD, were lower in African-Americans (men and women) when compared with Caucasians (P < 0.05). Serum calcium corrected for albumin was higher in the African-Americans than in the Caucasians (P < 0.05). As previously reported in Caucasians, PTH was inversely related to log 25OHD in African-Americans. Serum osteocalcin was positively correlated to PTH in African-Americans, as previously reported in Caucasians. Log 25OHD correlated inversely with osteocalcin in African-Americans, but this was not seen in Caucasians. CONCLUSIONS: In this limited sample, hypovitaminosis D (as assessed by 25OHD level) with secondary hyperparathyroidism occurred frequently in elderly African-Americans. Osteocalcin, a measure of osteoblast activity, correlated with 25OHD and parathyroid hormone. Osteocalcin serum levels were lower in African-Americans than Caucasians, but serum calcium corrected for albumin was higher in the former compared to the latter.

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