METHODS: A systematic literature search was performed in Scopus, Embase, Web of Science, and PubMed databases up to February 2020 for RCTs that investigated the effect of DHEA supplementation on testosterone levels. The estimated effect of the data was calculated using the weighted mean difference (WMD). Subgroup analysis was performed to identify the source of heterogeneity among studies.

RESULTS: Overall results from 42 publications (comprising 55 arms) demonstrated that testosterone level was significantly increased after DHEA administration (WMD: 28.02 ng/dl, 95% CI: 21.44-34.60, p = 0.00). Subgroup analyses revealed that DHEA increased testosterone level in all subgroups, but the magnitude of increment was higher in females compared to men (WMD: 30.98 ng/dl vs. 21.36 ng/dl); DHEA dosage of ˃50 mg/d compared to ≤50 mg/d (WMD: 57.96 ng/dl vs. 19.43 ng/dl); intervention duration of ≤12 weeks compared to ˃12 weeks (WMD: 44.64 ng/dl vs. 19 ng/dl); healthy participants compared to postmenopausal women, pregnant women, non-healthy participants and androgen-deficient patients (WMD: 52.17 ng/dl vs. 25.04 ng/dl, 16.44 ng/dl and 16.47 ng/dl); and participants below 60 years old compared to above 60 years old (WMD: 31.42 ng/dl vs. 23.93 ng/dl).

METHODS: Electronic databases (Scopus, PubMed/Medline, Web of Science, Embase and Google Scholar) were searched for relevant literature published up to February 2020.

RESULTS: Twenty-four qualified trials were included in this meta-analysis. It was found that serum IGF-1 levels were significantly increased in the DHEA group compared to the control (weighted mean differences (WMD): 16.36 ng/ml, 95% CI: 8.99, 23.74; p = .000). Subgroup analysis revealed that a statistically significant increase in serum IGF-1 levels was found only in women (WMD: 23.30 ng/ml, 95% CI: 13.75, 32.87); in participants who supplemented 50 mg/d DHEA (WMD: 15.75 ng/ml, 95% CI: 7.61, 23.89); in participants undergoing DHEA intervention for >12 weeks (WMD: 17.2 ng/ml, 95% CI: 8.02, 26.22); in participants without an underlying comorbidity (WMD: 19.11 ng/ml, 95% CI: 10.69, 27.53); and in participants over the age of 60 years (WMD: 19.79 ng/ml, 95% CI: 9.86, 29.72).

PURPOSE: The purpose of this clinical study was to determine the prevalence of type of posterior mandibular ridge morphology in a Malaysian population and to evaluate the buccolingual width of the alveolar ridge (Wb and Wc); alveolar ridge height (Vcb); and concavity angle, length, and depth for both left and right first and second molars in different age groups and sexes by using cone beam computed tomography (CBCT).

MATERIAL AND METHODS: Bilateral posterior mandibular lingual concavities at the first and second molars were retrospectively studied in cross-sectional views of 150 CBCT scans (n=600 sites evaluated). The sample size was calculated at a power of 80%, confidence interval of 95%, and margin of error of .05. The buccolingual width from the base and crest of the ridge and the ridge height were measured to determine the type of ridge. For the U-shaped ridge, the concavity angle, length, and depth were assessed. The independent t test was used to compare mean values of CBCT measurements between sexes and tooth type, while the ANOVA and Pearson chi-squared test were used to determine the correlations with age groups and types of ridge morphology, respectively. To compare the left and right readings for first and second molars in the same patient, the paired t test was performed (α=.05 for all tests).