Dietary patterns, eating behaviors, and bone mineral density in women runners.

Although reduced gonadal steroid hormone concentrations appear to play a major role in lower trabecular bone mineral density (BMD) in women with athletic amenorrhea, dietary deficiencies and eating behaviors may also affect BMD in women runners. To investigate this possibility, dietary patterns (7-d records), eating-disorders inventory (EDI), and BMD were examined in nine nonrunning eumenorrheic control (Contl) and 32 women runners classified as eumenorrheic (n = 19, Eumen) and oligo/amenorrheic (a group in which some were oligomenorrheic and some were amenorrheic; Ol/Am, n = 13). Runner groups had similar cardiorespiratory fitness, body composition, and training characteristics. Lumbar spine BMD was lower in the Ol/Am runners (-12%, P less than 0.05) but proximal femur BMD did not differ. Dietary intake and EDI subscale scores were similar among the groups. However, there was an inverse trend between EDI subscale scores for bulimia and ineffectiveness and femoral BMD in the Ol/Am runners (r = -0.62 to -0.71, P less than 0.05). These results suggest that self-reported dietary intake and/or eating behaviors do not predict reproductive-function alterations in women runners, but eating behaviors may be associated with lower BMD in Ol/Am runners.

A noninvasive scintigraphic assessment of the colonic transit of nondigestible solids in man.

A noninvasive, scintigraphic technique for quantifying large intestinal transit time that provides low radiation doses was developed. The scintigraphic large intestinal transit (SLIT) method uses a total of 100 microCi of 111In encapsulated in ten 2-cm nondigestible capsules, which are ingested after a 6-hr fast. Two hundred fifty microcuries of 99mTc-sulfur colloid were given to outline the gastrointestinal tract. Images were acquired at 4-hr intervals until all capsules were excreted. Normal volunteers (n = 10) consumed a standardized diet 2 days prior and during imaging. Segmental transit times were measured in the following: ascending, transverse, descending, recto-sigmoid colons; hepatic and splenic flexures. The radiation absorbed dose to the large intestine for the SLIT technique is less than half of that associated with other radiographic methods of colonic transit time measurement.