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Biomedical subjects

N W Shock

Publications and source records attributed to N W Shock.

At least 19 recordsLinked to original sources
PubMed1987

Hypertension and the kidney.

The purpose of this study was to confirm, using longitudinal observations in a normal population, that the rate of decline in renal function (creatinine clearance) is inversely correlated with blood pressure. The negative regression coefficients plotting individual rates of decline over time (Bcr) against mean blood pressures (MBP) were highly significant (p less than 0.001) for all subjects and subjects in category 3 (normals). Although the Bcr also decreases significantly with age and MBP increases with age suggesting this might be an age effect, a multiple regression analysis shows that both MBP and age as independent variables exert statistically significant effects on Bcr, the dependent variable.

Adult↗
PubMed1985

Longitudinal studies on the rate of decline in renal function with age.

Serial creatinine clearances (5 to 14 studies) were obtained for 446 normal volunteers in the Baltimore Longitudinal Study of Aging followed between 1958 and 1981. When those subjects with possible renal or urinary tract disease and subjects on diuretics and antihypertensives were removed from the study, leaving a group of 254 "normal" subjects, the mean decrease in creatinine clearance was 0.75 ml/min/year. The slopes of the creatinine clearance vs. time fell into a normal (Gaussian) distribution around this mean. One third of all subjects followed had no absolute decrease in renal function (positive slope of creatinine clearance vs. time) and there was a small group of patients who showed a statistically significant increase (P less than 0.05) in creatinine clearance with age.

Adult↗
PubMed1984

Association between blood pressure and the rate of decline in renal function with age.

A significant negative correlation (P less than 0.0001) exists between the mean blood pressure (MBP) and the rate of decline in creatinine clearance with time in years (BCr) in 446 subjects in the Baltimore Longitudinal Study on Aging (BLSA) followed serially on five or more visits over a period of 8 or more years. Even when the 118 subjects with possible renal and/or urinary tract pathology (category 1) and 74 subjects treated with diuretic and/or antihypertensive agents (category 2) were not included, this relationship remained in the 254 "normal" (category 3) subjects. Since both MBP and negativity of the BCr tend to increase with age, multiple regression analyses using both MBP and age as independent variables were performed to determine their respective influences on BCr. Both MBP and age significantly influenced BCr. When those subjects with hypertension (mean MBP greater than 107 mm Hg) were not included, however, the inverse relationship between MBP and BCr is lost, suggesting that an accelerated loss of renal function is observed primarily because of the impact exerted by individuals with blood pressures in the hypertensive range.

Adult↗
PubMed1982

The role of nutrition in aging.

Nutritional requirements do not change appreciably with age among adults. However, with increasing age total caloric intake is gradually reduced, but among normal people living in the community dietary deficiencies are seldom found. Deficiencies in specific nutritional elements are found among poor and disadvantaged elderly people. The use of special diets or the ingestion of megadoses of vitamins do not improve health or prolong life. The reduction in food intake and the tendency of old people to eat the same diet day after day makes them potentially vulnerable to possible deficiencies in specific vitamins, minerals, and protein. In most animal species (rats, mice, fruit flies, rotifers), a reduction in the daily food intake over the entire life-span increases it. The mechanisms of this increase are not known. Although there are rational reasons to believe that nutrition must play an important role in aging, experimental data to prove relationships are most scanty. The field of nutrition and gerontology share many difficulties, viz the lack of a biological index of aging and an index of optimal nutrition in individual adults. Research on these basic issues is essential before we can give definite answers to the questions about relationships between nutrition and aging.

Aging↗